Clear, articulate, precise. As a fellow Algebra Teacher I really enjoyed watching your instruction, I picked up a couple of things to use in my own class. Good Job
Hearing that teachers are out here engaging in their own development warms my heart. Thank you so much. I’m coming back to quadratics after ten years of failing it at school. My algebra teacher yelled at me for asking for real world examples so I could try learn quadratics application. Now it all is making sense!!!!
@@jessalisauskas7069 I don't really look back at any of my videos, so after recording them I hope that even years down the line it can still all make sense in such a way that people will engage in it and it is relevant to their coursework (especially when things like factoring and completing the square is involved). It seems this video is really doing it for people, and I'm just hoping that it's good enough!
Hey! You are amazing! I have been stuck on this subject since last week. You were the best teacher I found here; you speak slowly, and I can see how much you enjoy teaching. In just one hour, you helped me understand everything. Thank you very much for helping so many students!
Saturday I have the Sat test and thanks to you I finally understood how to complete the square and use in word problems the vertex form. Thank you so much for your help from Italy 🥇
What a great video! Thank you Professor Robinson. I especially like when you point out the fact that that parabolic curve does not mean that the object is moving from left to right as time progresses. As you point out, rather in refers to the change in height as time progresses. That is such a helpful hint, and I will use it in my session today with my students. Thank you again.
Thanks for the kudos, Dr. Mike! And please, I'm just Mr. Robinson haha! Although coincidentally enough, in my dream I brought my father into my classroom (who was a professor) and said to differentiate us, I would be Mr. and he would be Prof. Of course, I am leaving out the nugget that he been passed for over nine years, and that's why it's great to still dream about him as often as I do. Enjoy your session today!! :)
Thanks! I'm glad to hear this video has proven helpful for you. It seems this also pops up in people's searches so I hope it continues to help others as it did you. :)
Let's hope this is already the case, and you're not just forecasting something which has yet to come!! Only tell me this after you take the tests haha. I'm glad to hear you're super confident, regardless! :)
Thank you i finally understand what i didnt understand and what i need to do to figure out these word problems you made it so simple and easy to understand you are a life saver!!!!! Better than that 1 khan academy video you gave multiple examples and this is truly ging to help me ik it is!!! Thank you!!!!
Definitely not late! It's here for you when you're ready for it! Hopefully 30 years from now people will still be using it the same way. :) Good luck tomorrow! Let me know if you have any questions.
@@MrRobinsonsMathChannel Actually, we only have physics next school year (I'm an incoming g12). I was watching your videos as a review for college entrance exam.
Omg im so happy to have found you tomorrow I have my ib Math hl and sl placement test and we had the hint of it being quadratics and factorisation, this has definitely helped me with review as I can’t do word problems to save my life
This is fantastic! I don't know how TH-cam recommends certain videos/channels over others and how mine compares to others for information, but if this helps you the way that you need then I am forever honored to serve you!, Sven! :)
Yeah I revisited this sheet in my classes this year, and I have a student named Jason. First I asked if he could jump 4 feet into the air, and later I had to comically apologize by saying: "Sorry Jason, you ain't surviving this one!" 😂
So so so helpful! I sent this video around to everyone in my class. With finals coming up this vid was a life saver!!! You have earned yourself a new sub! :)
Hey awesome, thanks for the mention and I hope this helps you all understand what you already knew just a little bit better. Shoutout to Abby Hanifin! :) Curious, what class are you taking and are there possibly other videos on my channel that you may like me to direct you toward?
@@MrRobinsonsMathChannel Thx for the response! I'm in high school level Algebra 2 Hnrs. I am about to watch your logarithmic properties video. Do you have any vids on exponential growth & decay? We sped over it in my class.
@@abbyhanifin Hmm, word problems or which kind? I'll track down what I have because there is definitely something, but it's a bit sporadic. I will apologize since my channel is somewhat cluttered regarding content (these are made for my classes first and foremost without a thought of who else may be watching, haha), so whether you or I navigate through it may be a bit of a time suck. I'll do my best though!
@@abbyhanifin Okay Abby, I may have something up your alley but I want to confirm this is what you're looking for before I show you more on it, because the problems on the video will not really be next to each other. Look to this PDF for things regarding exponential functions: smallpdf.com/file#s=07b942f0-296d-4a51-96ba-39609f6f1b60 Page 1 has graphing basic exponential functions (no shifts, though I have videos with those if you need them), and pg. 2-3 has growth/decay model word problems. Are any of these of interest to you?
Thank you🩵 I gonna retest next week. I’m a foreigner and I not good in English, so I don’t understand my teacher😅.In class don’t have translate subtitles like TH-cam😂 anyway you teach very well.🤩
i seriously wish you were my teacher! im likely to fail my test tomorrow, but it will be better after watching this! my english isnt very fluent so i dont understand a word my teacher says hahahaha 🥲very difficult without your video
Oh man, I totally should but it is easier if I'm teaching the classes so I can start to anticipate certain things, like questions students would have, student mistakes, and how I would creatively attack problems in different ways. Definitely not in the groove to get big right now into it, but I imagine in the future (when you're long past getting an education hahaha) I might be jumping into the Calc realm! Thanks. :)
@@Concraft Haha oh man, I'm sorry about that! Yeah I definitely won't have the time to be able to muster through any calc stuff this year sadly, it's all devoted to Integrated Math 1 & 3 material.
I have a math test tomorrow and this really helped me so much, Thank you sir!! I had a question.. So what about the questions like how wide and tall is the parabola? Do you like add the x-intercept for how wide and for tall you figure out the vertex?
Good luck! Sorry for not seeing this sooner. Yes, and if you want more there are some questions in this video exactly like that (check out #27-29, which spring to mind): th-cam.com/video/eCVu0LrtY0Y/w-d-xo.htmlsi=TJ-ZgAWPgtb6UFFZ&t=4456
Internet, my friend! I don't know if it was all one PDF, or if it was one that we assembled as a department, or if I said "I like these altogether" and I collected them all. Totally forgetful haha. Thanks a bunch!
Dammit Jason.... Thnx professor, doin precalc after 11 years away from education. I caught up pretty fast but these word problems have been the death of me... No pun intended
LOL TH-cam is a great platform for keeping these archived for the ages! I'm not teaching material this year that covers this, but I'm glad that in the future I can go straight back to this assignment myself and say "Here kids, watch this video if you need" and don't have to re-record it again. Glad that others stumble upon it along the way!
At 23:17, shouldn't the acceptable answer only encompass 1 instead of both 1 and 7? Because it talks about after how many seconds will the rocket be, so after how many seconds after it took off from ground level? Thanks for your educational channel, it's been very helpful.
Hey, sorry that I completely missed your comment! Not sure if I understand your justification though. I keep re-reading it and I'm trying to figure out why it should only be 1 and not 7. I feel like for this problem type (and problems of the sort), they really do want you to find both answers. The only times they don't are when you have numbers outside of the domain, like getting negative time values that wouldn't apply to the model. Thanks for the props, though! I hope everything else was very helpful a couple of months ago! :D
only 6 minutes into the video and I am glad to have seen your account thanks man!!!! im in grade 10 and am a 60% student in math do you think I can still improve ?
Everyone can improve! The first valuable resource to overcome though, of course, is time. It takes a bunch of practice within, but yeah man it can happen! I'm glad you found this video helpful, and I hope I'll continue being able to help you in the future!!
@@Ronaldogoat2107 Well, my TH-cam channel contains loads of other videos that are perhaps relevant to what you're doing. I know they can be difficult to search for (even for myself sometimes), but if you type "Mr. Robinson" followed by some math topic, it's possible that you might find something you're looking for!
Thanks Professor Robinson for all clear explanation, but what I need I to request 2 questions (1) when did we use Discrimination =b^_2ab And how this formula drive from request full proof (2) how they drive from proof all in real life meaning if you don't mind. a) y =mx +b b) y= ax+b+c C) y = ax^+bx +c d) y =(x_h)^+k e) y =a(x_h)^+k f) y =a(x_s)(x_r) g) x= - b/2a Thanks
Unfortunately, I'm not sure how to answer the questions you're asking... mainly because I don't understand WHAT questions you're asking. Half of the formulas you wrote aren't even formulas themselves, or you're using incorrect symbols. If you can find a way to rephrase the questions, I'll make my best attempt to answer these questions. However, if they are not very answerable in text form, sadly I'm not sure how much I'll be able to help you regardless! I hope we can figure out what it is you're asking and get it taken care of. :)
Haha hardly a legend! Though coincidentally I was just telling my students "I hope my videos are still up after I die and people would comment later saying 'Mr. Robinson still be teaching us from beyond the grave!'" That's kind of a neat idea. I sure hope that's not for a long while though, heh.
Hii, do u think u could do word problems that don't give you an equation but just height and width of something? I had a question about some bridge with certain measures and i didnt understand the question since i expected an ecuation :(
Perhaps! I'm not thinking of that type of question off the top of my head right now, though. If you recall what that question is later or have it on-hand, feel free to send it my way! :)
On problem b I was stuck on the calculator part because at first you were talking about a discriminatory. I was just wondering that if we skipped the discriminatory part, if we could just the -b plus or minus the square root of -4 times a times b.
By "problem b," do you mean for #3? Yes, you can go straight to the quadratic formula. I do the discriminant first to expedite the process, because most of the work is done inside there (I explain that in other videos where my primary focus is the quadratic formula).
I’m sorry if this is a dumb question I’m just a little confused at 21:50 how are we getting t=7,1? wouldn’t -7 * 1 = -7? and -7 + 1 = -6 so how did we get it do add to -8? Thank you for your time
Hi Chloe. I think I see where I stirred you wrong. Out loud I indeed said "Negative 7 and positive 1," although I wrote -7 and -1. What I wrote was correct, what I said would be incorrect. Why did I say it? Not sure. Maybe when I said the 1 I was thinking about the answer that it would become. Just a brain fart, I suppose. I'm due for one or two of those. :)
Hi Mr Robinson, I'm two years late and it's kind of a dumb question but would that formula you used at the start for half a second be okay to use to find the TP of other quadratics? -(b)/ 2(-b). I'm just wondering because I was somehow never taught that there was another much shorter formula to find the TP
@@Elaine-kd6ri It's really cool once you find all the different ways that math connects to itself, or how you can use a proof to make one match with another. Glad you ran into the answer that you were looking for, Elaine! Oh, and don't think that you are late at all. This video is meant for you at YOUR convenience, and nobody else's. Twenty years from now, students who still won't even be alive through the next presidential term should be able to ask me a question about this video, and it would not be "too late" at all then, either! I'm glad this was able to help in some way. :)
@@MrRobinsonsMathChannel lol you're right, if I become in a math teacher in 20 years I'll be pointing them in your direction! thank you for the help :))
Mr. Robinson, a doorway has a parabolic arch. The base of the doorway is 3m wide. At a point 1.0m from one side of the doorway, it is 3m high. How do you determine an equation to represent this function?
Assuming we're placing one side of the doorway's base at (0, 0), that means we can place the other side at (3, 0). A third point we also will have is (1, 3). These are three (x, y) values that we can use to make an equation using the form y = ax^2 + bx + c. Your goal will be to find the a, b, and c that satisfy an equation in that form. Generally in the case of not knowing what your vertex is (even though we know the x value would be 1.5 since it's halfway between 0 and 3, we don't know what the y value will be), you would set up a system of three equations using your three (x, y) values in separate equations. In this case, using y = ax^2 + bx + c, your system would look like this: (0, 0) --> 0 = a(0)^2 + b(0) + c (3, 0) --> 0 = a(3)^2 + b(3) + c (1, 3) --> 3 = a(1)^2 + b(1) + c If I clean up each equation and put the y values on the right side, they'd look like this: c = 0 9a + 3b + c = 0 a + b + c = 3 Solving this system helps a lot because you get a true value for c as 0, meaning you can substitute that in the bottom two equations and get a system of two: 9a + 3b = 0 a + b = 3 You have a lot of options on what to do here, once of them being using the elimination method by rewriting an equation so that it cancels out one of your variables. If we divide the top equation by -3, we get: -3a - b = 0 a + b = 3 And adding these two equations, the b's eliminated and we get: -2a = 3 a = -3/2 = -1.5 Now we have the value for 'a'. Let's substitute that value into the equation a + b = 3 and solve for b: -1.5 + b = 3 b = 4.5 Okay, so a = -1.5, b = 4.5, and c = 0. So for our general quadratic equation y = ax^2 + bx + c, our final answer will be: y = -1.5x^2 + 4.5x I hope that helps! :)
Hi for question 2b. I was taught to always have the -16^2 to be kept as positive. So as the equation would be 112=-16t^2+128t i flipped it to 16t^2-128t+112. Then using the quadratic formula i got 1.7 and 6.2. Any idea why
Hi tripyyy, First of all, I think you were taught well to always keep it positive! You'll find that I do this on 3b (see 29:36). It benefits you in the long run, especially when it comes to work in the denominator. Heck, in any other problem where I do factoring (such as 2b), I also factor out the leading negative. As far as your solutions, I suppose what we would need to do is inspect your work. Even if you have the equation 16t^2 - 128t + 112 = 0 (and don't forget that zero, by the way), You should still ultimately get t = 1 and t = 7 by using the quadratic formula. Now, I'm a fan of dividing out common factors as I did (such as 16), but let's say you kept your numbers in there. So your formula would look like: t = [ -(-128) +/- sqrt( (-128)^2 - 4(16)(112) ) ] / [ 2(16) ] t = [ 128 +/- sqrt(16384 - 7168) ] / 32 t = [ 128 +/- sqrt(9216) ] / 32 t = [ 128 +/- 96 ] / 32 *t = 224/32 = 7* *t = 32/32 = 1* Check all of your values to see that you're substituting and simplifying properly. Feel free to check back with me on where you might have gone wrong, and I'll be happy to help you out! :)
@@MrRobinsonsMathChannel Thank you so much for helping out. I see my fault. I may or may not have made a mistake in the square of 128. Idk why lol. Thank you so much for the help
Can you help me I gotta study all those for my mid semester and I don’t know anything about them factor out a monomial, factor quadratics with leading coefficient 1, factor quadratics with other leading coefficients, factor quadratics: special cases, factor by grouping, solve a quadratic equation using the zero product property, solve a quadratic equation by factoring, solve quadratic equations: word problems
That's quite a handful! I have several videos on my channel regarding all of those. There are some in immediate sequence of another, some from certain textbooks (such as my Big Ideas Math run), etc. I could link you to some of those, but if you type some of those keywords in when searching for my channel you'll find the whole set of them!
Glad to hear that even a few years later people like you can always continue to be helped! You're welcome, as this video isn't going down any time soon! :)
Yes, of course! I try and avoid using completing the square unless I have an even linear coefficient (after factoring out anything in front of my quadratic term). See that you get the same answer by doing that if you try. :)
-b/2a is the way to find the x value of any vertex for a quadratic equation written in standard form. I don't suppose this comment section is the time to explain why this is the case, but if you know Calculus or look into the quadratic formula a bit you might see why this is true. Just keep in mind that this video is teaching word problems for quadratic equations, so I'm somewhat assuming we know how to use certain things on quadratic equations when you enter the video, such as finding the vertex. :) Thanks so much for asking!! Let me know if there is any other way I can help you!
Hmm, do you mean like area/volume kinds of questions? A couple of my recent videos had some problems out of the textbook for sure. I'll have to search far and wide for them, but anything from Chapters 2-4 where they have word problems on Modeling Mathematics may have something you're looking for!
Where are you referring to this in particular? If you mean with regard to the functions, yes time is being squared, but it is a model representing HEIGHT as a function of time. So the question as to why "time is squared" is answered by the fact that the height of the object is dependent on it. Why does it depend on it? Gravity. Gravity is a force based upon acceleration, which means it expressed not how much an object changes position over time, but how much it changes velocity over time. Its units are not feet per second (ft/sec), but rather feet per second per second (ft/sec^2). This is what creates the parabolic arc of height (once again, due to gravity), and that occurs in the form of a quadratic model.
After setting up my quadratic equation -16t^2 + 16t + 480 = 0, my personal plan for solving was by use of factoring and the zero-product property. My first step in factoring was seeking a greatest common factor (GCF), and that value happened to be a -16. That means that I can divide -16 among all of my terms, and what I wrote inside the parentheses is what each value becomes after that division: -16 ( t^2 - t - 30 ) = 0 So, where does -30 come from? 480 divided by -16. If you distribute that -16 back into all three terms, you will restore the original equation that we have set up, where -16 * -30 = 480 as well. Hopefully that helps!
Fair enough. I can speed run through these questions as well (I can finish this whole assignment in under ten minutes), but the point of *my* videos personally are to teach the material itself to cater to the lowest common denominator (those learning it for the first time). I can excuse that by saying that one who is watching can still speed up the video, scrub through it, fast-forward it, or skip it entirely. There are other TH-cam videos out there that have expedited versions, and mine tend to not be those. I do have videos like that here and there though, and you'll find them; of course, whenever I do make these, I'll have several students that say I go too fast and don't explain a step that they wanted. In other words, I'm not doing the problems to teach the material (this is not what teachers SHOULD do with examples either). Instead, I am using the material to support what it is that I'm teaching. That way, when a student attacks a problem with some variations to it, they aren't completely dumbfounded because "it's not exactly like the last one but with different numbers." They have the luxury of opportunistically seeing more angles to it and they have a more general feel of what's happening. This is a conversational piece to give students an inner dialogue, particularly my students. I'm sure you know the Abraham Lincoln quote (which always changes the time around), saying something like: "If I had an hour to chop down a tree, I'd spend the first 45 minutes sharpening my axe." This video is mostly axe-sharpening, and then I chop away when I'm ready to go. By the way, I'm not saying you're wrong on how I approach these. I'm just saying that this is an intentional stylistic approach that I choose to use. I agree, we don't have 15 minutes to spend on a problem. Thankfully, these problems aren't your test. If you're interested in sending me a PDF of a word problem sheet that you have, I'll happily make a 15-20 minute version of a similar thing in contrast to this one though! :)
@@MrRobinsonsMathChannel Thank you so much for the offer and feedback, i understand what your trying to bring through these videos and its very much appreciated, My test is tomorrow therefore probably not enough time to make an explanation video
Hi there, it depends on how you're entering this as a whole. If you don't know the background behind factoring, quadratic formula, completing the square, vertexes, etc. then it can definitely be a daunting task. The purpose of this video was less on teaching how to do THOSE specific things (though I have videos on them if you want to hear more), but rather how to interpret the word problems as a whole. If you're still having trouble on the latter portion, I'm sorry that my video wasn't enough help on clarifying those portions.
Hmm, well I guess the bigger question is why would it be 6.75 feet? I showed where I calculated 2.25 feet from. I don't know how else I can explain "why it is what I calculated" outside of what I showed on the screen. I don't know where 6.75 feet comes from, or rather how a human jumps that high in the air to begin with haha. Did you do 9/4 + 9/2? I believe the 9/4 is negative when you multiply -16 by the squared value. Maybe that's where you got 6.75 from.
Hahaha never heard of him! Just looked him up, and I actually think one of my students from last year even looks much more like him, and I think he'd agree. But hey, if it's a compliment, then I'll take it! If not... well... I hope the video helped you! 😆
This video I watched at lunch before my test helped me understand the big point question and get an A thank you sir
Oh dang that's awesome!!
2 years later and still saving people before their exams THANK YOU SO SO MUCH!!🙏🙏
Hehe well the math doesn't change two years later, so it's understandable that it'll still help. 😁
Appreciate the kudos!!
Holy, one day ago and he replied
Clear, articulate, precise. As a fellow Algebra Teacher I really enjoyed watching your instruction, I picked up a couple of things to use in my own class. Good Job
I think that's the highest praise that I can receive! That's really cool to hear, thank you! If you have anything to offer, I'm all ears!
Hearing that teachers are out here engaging in their own development warms my heart. Thank you so much.
I’m coming back to quadratics after ten years of failing it at school. My algebra teacher yelled at me for asking for real world examples so I could try learn quadratics application. Now it all is making sense!!!!
@@jessalisauskas7069 I don't really look back at any of my videos, so after recording them I hope that even years down the line it can still all make sense in such a way that people will engage in it and it is relevant to their coursework (especially when things like factoring and completing the square is involved).
It seems this video is really doing it for people, and I'm just hoping that it's good enough!
Hey! You are amazing! I have been stuck on this subject since last week. You were the best teacher I found here; you speak slowly, and I can see how much you enjoy teaching. In just one hour, you helped me understand everything. Thank you very much for helping so many students!
Normally I'm accused of talking too quickly haha. I'm glad my content works for you though! Thanks for the feedback. 🙂
Saturday I have the Sat test and thanks to you I finally understood how to complete the square and use in word problems the vertex form.
Thank you so much for your help from Italy
🥇
Awesome! Best of luck to you!!!
What a great video! Thank you Professor Robinson. I especially like when you point out the fact that that parabolic curve does not mean that the object is moving from left to right as time progresses. As you point out, rather in refers to the change in height as time progresses. That is such a helpful hint, and I will use it in my session today with my students. Thank you again.
Thanks for the kudos, Dr. Mike! And please, I'm just Mr. Robinson haha!
Although coincidentally enough, in my dream I brought my father into my classroom (who was a professor) and said to differentiate us, I would be Mr. and he would be Prof.
Of course, I am leaving out the nugget that he been passed for over nine years, and that's why it's great to still dream about him as often as I do.
Enjoy your session today!! :)
keep these videos coming dude! these problems are quite entertaining to do, especially with you!
Appreciated! I'm not teaching IM2 this year though so don't expect any more quadratic word problems this year ahaha.
Bro, your the only teacher who actually teaches this well. Wish you were my actual teacher. Thank you so much.
Earned a Sub👍
Thanks! I'm glad to hear this video has proven helpful for you. It seems this also pops up in people's searches so I hope it continues to help others as it did you. :)
Keep up the good work man. Really appriciate it. Il definently be coming back for more help@@MrRobinsonsMathChannel
sir you just saved my test scores... thank you so much!
Let's hope this is already the case, and you're not just forecasting something which has yet to come!! Only tell me this after you take the tests haha.
I'm glad to hear you're super confident, regardless! :)
I don't understand help me plz@@MrRobinsonsMathChannel
Thank you i finally understand what i didnt understand and what i need to do to figure out these word problems you made it so simple and easy to understand you are a life saver!!!!! Better than that 1 khan academy video you gave multiple examples and this is truly ging to help me ik it is!!! Thank you!!!!
Thanks! I shared this with my lovely students and they agreed! I appreciate the words!
3 years late but thank you so much! Have a college algebra quiz tomorrow and was really confused, but this helped so much. :)
Definitely not late! It's here for you when you're ready for it! Hopefully 30 years from now people will still be using it the same way. :)
Good luck tomorrow! Let me know if you have any questions.
Wow, this video really helped me understand how to attempt these word problems in 20 minutes! Keep up the great teaching!!!
I plan on it, haha! Thanks, RexMon!
OMG love the hockey game at the back
giving cozy vibes
Thank you! Others despise it, calling it a distraction haha.
I literally had to teach the first part in 3 hours and this helped a lot.
Haha which first part? Like #1?
Glad this helped! Good luck if you still have yet to teach it!
thank you Mr. Robinson, I hope you'll still continue on teaching
Oh absolutely! Do you mean teaching, or recording videos? Haha either way you'll get the best of both worlds!
What math are you going into next year?
@@MrRobinsonsMathChannel Actually, we only have physics next school year (I'm an incoming g12). I was watching your videos as a review for college entrance exam.
@@tahopeya Oh no way, alright! Best of luck to ya!!
Omg im so happy to have found you tomorrow I have my ib Math hl and sl placement test and we had the hint of it being quadratics and factorisation, this has definitely helped me with review as I can’t do word problems to save my life
This is fantastic! I don't know how TH-cam recommends certain videos/channels over others and how mine compares to others for information, but if this helps you the way that you need then I am forever honored to serve you!, Sven! :)
This was literally my notes in class today
what an great teacher I appreciate you alot
Thank you!!! Such high quality videos I feel like getting you a Christmas gift 😭😭
No needs, Tate! Just keep giving the gift of A's!
My gosh, that sounded corny. Have a good one!! :)
Jason gotta be a superhuman on vacation if he's jumping 4 feet into the air, off a 480 feet cliff and into the water
Yeah I revisited this sheet in my classes this year, and I have a student named Jason.
First I asked if he could jump 4 feet into the air, and later I had to comically apologize by saying: "Sorry Jason, you ain't surviving this one!" 😂
🙏 My teacher was sick so she didn’t explain this but still said it would be on the test but this has helped me so much! Thank you!
Heyyooo, I began doing this for my students in case they were sick or I was! Turns out that I never really am, but they are all the time! 😆
Thanks!
So so so helpful! I sent this video around to everyone in my class. With finals coming up this vid was a life saver!!! You have earned yourself a new sub! :)
Hey awesome, thanks for the mention and I hope this helps you all understand what you already knew just a little bit better. Shoutout to Abby Hanifin! :)
Curious, what class are you taking and are there possibly other videos on my channel that you may like me to direct you toward?
@@MrRobinsonsMathChannel Thx for the response! I'm in high school level Algebra 2 Hnrs. I am about to watch your logarithmic properties video. Do you have any vids on exponential growth & decay? We sped over it in my class.
@@abbyhanifin Hmm, word problems or which kind? I'll track down what I have because there is definitely something, but it's a bit sporadic.
I will apologize since my channel is somewhat cluttered regarding content (these are made for my classes first and foremost without a thought of who else may be watching, haha), so whether you or I navigate through it may be a bit of a time suck. I'll do my best though!
@@abbyhanifin Okay Abby, I may have something up your alley but I want to confirm this is what you're looking for before I show you more on it, because the problems on the video will not really be next to each other.
Look to this PDF for things regarding exponential functions:
smallpdf.com/file#s=07b942f0-296d-4a51-96ba-39609f6f1b60
Page 1 has graphing basic exponential functions (no shifts, though I have videos with those if you need them), and pg. 2-3 has growth/decay model word problems. Are any of these of interest to you?
@@MrRobinsonsMathChannel Yes!! The word problems on pages 2-3 are exactly what we are doing!
Thank you🩵 I gonna retest next week. I’m a foreigner and I not good in English, so I don’t understand my teacher😅.In class don’t have translate subtitles like TH-cam😂 anyway you teach very well.🤩
Thanks! Subtitle translations is one of the exact reasons I make videos for my students! I have a lot of English learners in my classes too. :)
i seriously wish you were my teacher! im likely to fail my test tomorrow, but it will be better after watching this! my english isnt very fluent so i dont understand a word my teacher says hahahaha 🥲very difficult without your video
I think I need you to be my new algebra teacher
Hahaha, well if you ever need any Zoom tutoring on the side, let me know and I'll see what I can do!
Thanks, and I hope you enjoyed the video!!
Awesome! I'll definitely recommend this vid to my students.
Nice! What class is it for?
love the hockey in the background...
Who doesn't?? :D
Really helps!!! Thank you very much for your amazing content
Anytime. Now go out there and conquer the world with your new knowledge!
hey, i just want you to know these videos were extremely helpful. thank you and keep up the good work.
Of course, glad to hear it! This seems to be the popular video lately haha.
you should do some calc 1 videos thanks
Oh man, I totally should but it is easier if I'm teaching the classes so I can start to anticipate certain things, like questions students would have, student mistakes, and how I would creatively attack problems in different ways.
Definitely not in the groove to get big right now into it, but I imagine in the future (when you're long past getting an education hahaha) I might be jumping into the Calc realm!
Thanks. :)
@@MrRobinsonsMathChannel i'll have to get through without you i guess. keep it up
@@Concraft Haha oh man, I'm sorry about that! Yeah I definitely won't have the time to be able to muster through any calc stuff this year sadly, it's all devoted to Integrated Math 1 & 3 material.
Thank you! Helped me understand my daughter's homework!
You're very welcome, Pam! Let me know if you have any other questions on the material. :)
I have a math test tomorrow and this really helped me so much, Thank you sir!!
I had a question..
So what about the questions like how wide and tall is the parabola?
Do you like add the x-intercept for how wide and for tall you figure out the vertex?
Good luck! Sorry for not seeing this sooner.
Yes, and if you want more there are some questions in this video exactly like that (check out #27-29, which spring to mind): th-cam.com/video/eCVu0LrtY0Y/w-d-xo.htmlsi=TJ-ZgAWPgtb6UFFZ&t=4456
@@MrRobinsonsMathChannel I finished my test and it was great thank you so much I recommend your videos to my friends who are also struggling in math.
@@CenchWench Let's goooo! Hope the test went well!!
Thank! This helped very much when i needed it. Where did you get your word problems by the way?
Internet, my friend! I don't know if it was all one PDF, or if it was one that we assembled as a department, or if I said "I like these altogether" and I collected them all. Totally forgetful haha.
Thanks a bunch!
i was so stressed for my test tmrw cause i studied so late but this helped so much!
How did it go??
Love it love just love it ❤❤❤❤❤ it a very clear conceptualization tnx .
I love when I can get people to love something about math, even if it's a video about it! Thanks Komal!! :D
Thank you! This video definitely helped me better understand quadratics! You are also very funny and a great teacher! :)
YAY! I love hearing that I'm funny. xD
Thanks Jerry!!
Dammit Jason....
Thnx professor, doin precalc after 11 years away from education. I caught up pretty fast but these word problems have been the death of me... No pun intended
LOL TH-cam is a great platform for keeping these archived for the ages! I'm not teaching material this year that covers this, but I'm glad that in the future I can go straight back to this assignment myself and say "Here kids, watch this video if you need" and don't have to re-record it again. Glad that others stumble upon it along the way!
Hocam Allah razı olsun , sesinize sağlık
Thank you! This helped!
Glad to hear it!
At 23:17, shouldn't the acceptable answer only encompass 1 instead of both 1 and 7? Because it talks about after how many seconds will the rocket be, so after how many seconds after it took off from ground level?
Thanks for your educational channel, it's been very helpful.
Hey, sorry that I completely missed your comment!
Not sure if I understand your justification though. I keep re-reading it and I'm trying to figure out why it should only be 1 and not 7. I feel like for this problem type (and problems of the sort), they really do want you to find both answers. The only times they don't are when you have numbers outside of the domain, like getting negative time values that wouldn't apply to the model.
Thanks for the props, though! I hope everything else was very helpful a couple of months ago! :D
only 6 minutes into the video and I am glad to have seen your account thanks man!!!! im in grade 10 and am a 60% student in math do you think I can still improve ?
Everyone can improve! The first valuable resource to overcome though, of course, is time. It takes a bunch of practice within, but yeah man it can happen!
I'm glad you found this video helpful, and I hope I'll continue being able to help you in the future!!
Thank you this helped me pass my test
Glad to hear it!!!
Thank you, this helps a lot!
All in a day's work, rae!
Im taking my math 2 test tomorrow but there also other topics other than this on that but this is still good practice
Good luck! I hope this helps cover a large portion of what you need. :)
@@MrRobinsonsMathChannelit’s a bit of it but yea
@@Ronaldogoat2107 Well, my TH-cam channel contains loads of other videos that are perhaps relevant to what you're doing.
I know they can be difficult to search for (even for myself sometimes), but if you type "Mr. Robinson" followed by some math topic, it's possible that you might find something you're looking for!
Thanks Professor Robinson for all clear explanation, but what I need I to request 2 questions
(1) when did we use Discrimination =b^_2ab
And how this formula drive from request full proof
(2) how they drive from proof all in real life meaning if you don't mind.
a) y =mx +b
b) y= ax+b+c
C) y = ax^+bx +c
d) y =(x_h)^+k
e) y =a(x_h)^+k
f) y =a(x_s)(x_r)
g) x= - b/2a
Thanks
Unfortunately, I'm not sure how to answer the questions you're asking... mainly because I don't understand WHAT questions you're asking. Half of the formulas you wrote aren't even formulas themselves, or you're using incorrect symbols.
If you can find a way to rephrase the questions, I'll make my best attempt to answer these questions. However, if they are not very answerable in text form, sadly I'm not sure how much I'll be able to help you regardless!
I hope we can figure out what it is you're asking and get it taken care of. :)
LEGENDDD 👑Thank YOUU!
Haha hardly a legend!
Though coincidentally I was just telling my students "I hope my videos are still up after I die and people would comment later saying 'Mr. Robinson still be teaching us from beyond the grave!'" That's kind of a neat idea. I sure hope that's not for a long while though, heh.
this video saved my life
I think I deserve some sort of award for that kind of high stakes rescue! ;)
I'm so glad it was helpful for you!!
God bless this man
I must thank the teachers before me who taught me this at one time or another!
Thanks Mr. Pearl, Mrs. Mills, Mr. Tsuchiyama, and Mr. Enenstein!
Thank you! This is super helpful!
Glad to hear it!
Hii, do u think u could do word problems that don't give you an equation but just height and width of something? I had a question about some bridge with certain measures and i didnt understand the question since i expected an ecuation :(
Perhaps! I'm not thinking of that type of question off the top of my head right now, though. If you recall what that question is later or have it on-hand, feel free to send it my way! :)
@@MrRobinsonsMathChannel Sure, tysm for your help anyways, your video made me understand lots of things i didnt before 😅.
@@-.kikuchiyuka6353 Always a genuine pleasure to hear this, truly!
THANK YOU SO MUCH!!!!
All in a day's work!!
On problem b I was stuck on the calculator part because at first you were talking about a discriminatory. I was just wondering that if we skipped the discriminatory part, if we could just the -b plus or minus the square root of -4 times a times b.
By "problem b," do you mean for #3?
Yes, you can go straight to the quadratic formula. I do the discriminant first to expedite the process, because most of the work is done inside there (I explain that in other videos where my primary focus is the quadratic formula).
I’m sorry if this is a dumb question I’m just a little confused at 21:50 how are we getting t=7,1? wouldn’t
-7 * 1 = -7? and -7 + 1 = -6 so how did we get it do add to -8? Thank you for your time
Hi Chloe! I'm seeing a -7 and a -1. So -7 * (-1) = 7 and -7 + (-1) = -8.
Let me know if I'm misreading your question. Thanks!
Hi Chloe. I think I see where I stirred you wrong. Out loud I indeed said "Negative 7 and positive 1," although I wrote -7 and -1. What I wrote was correct, what I said would be incorrect.
Why did I say it? Not sure. Maybe when I said the 1 I was thinking about the answer that it would become. Just a brain fart, I suppose. I'm due for one or two of those. :)
Hi Mr Robinson, I'm two years late and it's kind of a dumb question but would that formula you used at the start for half a second be okay to use to find the TP of other quadratics? -(b)/ 2(-b). I'm just wondering because I was somehow never taught that there was another much shorter formula to find the TP
negative b over 2a* sorry :'D
nevermind i watched the whole video properly- it appears that it DOES work
@@Elaine-kd6ri It's really cool once you find all the different ways that math connects to itself, or how you can use a proof to make one match with another. Glad you ran into the answer that you were looking for, Elaine!
Oh, and don't think that you are late at all. This video is meant for you at YOUR convenience, and nobody else's. Twenty years from now, students who still won't even be alive through the next presidential term should be able to ask me a question about this video, and it would not be "too late" at all then, either!
I'm glad this was able to help in some way. :)
@@MrRobinsonsMathChannel lol you're right, if I become in a math teacher in 20 years I'll be pointing them in your direction!
thank you for the help :))
this is so good thank u sm!!!
All in a day's work, human! :p
math test tomorrow i hope i do well 🥲@@MrRobinsonsMathChannel
I have exams this week wish me luck🙏🏽
Oh shoot, good luck my friend! I suppose just loop this bad boy on repeat until you got it nailed! :D
Mr. Robinson, a doorway has a parabolic arch. The base of the doorway is 3m wide. At a point 1.0m from one side of the doorway, it is 3m high. How do you determine an equation to represent this function?
Assuming we're placing one side of the doorway's base at (0, 0), that means we can place the other side at (3, 0). A third point we also will have is (1, 3). These are three (x, y) values that we can use to make an equation using the form y = ax^2 + bx + c. Your goal will be to find the a, b, and c that satisfy an equation in that form.
Generally in the case of not knowing what your vertex is (even though we know the x value would be 1.5 since it's halfway between 0 and 3, we don't know what the y value will be), you would set up a system of three equations using your three (x, y) values in separate equations.
In this case, using y = ax^2 + bx + c, your system would look like this:
(0, 0) --> 0 = a(0)^2 + b(0) + c
(3, 0) --> 0 = a(3)^2 + b(3) + c
(1, 3) --> 3 = a(1)^2 + b(1) + c
If I clean up each equation and put the y values on the right side, they'd look like this:
c = 0
9a + 3b + c = 0
a + b + c = 3
Solving this system helps a lot because you get a true value for c as 0, meaning you can substitute that in the bottom two equations and get a system of two:
9a + 3b = 0
a + b = 3
You have a lot of options on what to do here, once of them being using the elimination method by rewriting an equation so that it cancels out one of your variables. If we divide the top equation by -3, we get:
-3a - b = 0
a + b = 3
And adding these two equations, the b's eliminated and we get:
-2a = 3
a = -3/2 = -1.5
Now we have the value for 'a'. Let's substitute that value into the equation a + b = 3 and solve for b:
-1.5 + b = 3
b = 4.5
Okay, so a = -1.5, b = 4.5, and c = 0. So for our general quadratic equation y = ax^2 + bx + c, our final answer will be:
y = -1.5x^2 + 4.5x
I hope that helps! :)
Thank Mr. Robinson I will drop a sub for sure! Keep up the excellent teaching, you saved my math grade🙏@@MrRobinsonsMathChannel
@@selfieg4m3r78 Haha preach, my friend! Glad to help. :)
Hi for question 2b. I was taught to always have the -16^2 to be kept as positive. So as the equation would be 112=-16t^2+128t i flipped it to 16t^2-128t+112. Then using the quadratic formula i got 1.7 and 6.2. Any idea why
Hi tripyyy,
First of all, I think you were taught well to always keep it positive! You'll find that I do this on 3b (see 29:36). It benefits you in the long run, especially when it comes to work in the denominator. Heck, in any other problem where I do factoring (such as 2b), I also factor out the leading negative.
As far as your solutions, I suppose what we would need to do is inspect your work. Even if you have the equation 16t^2 - 128t + 112 = 0 (and don't forget that zero, by the way), You should still ultimately get t = 1 and t = 7 by using the quadratic formula. Now, I'm a fan of dividing out common factors as I did (such as 16), but let's say you kept your numbers in there. So your formula would look like:
t = [ -(-128) +/- sqrt( (-128)^2 - 4(16)(112) ) ] / [ 2(16) ]
t = [ 128 +/- sqrt(16384 - 7168) ] / 32
t = [ 128 +/- sqrt(9216) ] / 32
t = [ 128 +/- 96 ] / 32
*t = 224/32 = 7*
*t = 32/32 = 1*
Check all of your values to see that you're substituting and simplifying properly. Feel free to check back with me on where you might have gone wrong, and I'll be happy to help you out! :)
@@MrRobinsonsMathChannel Thank you so much for helping out. I see my fault. I may or may not have made a mistake in the square of 128. Idk why lol. Thank you so much for the help
Can you help me I gotta study all those for my mid semester and I don’t know anything about them factor out a monomial, factor quadratics with leading coefficient 1, factor quadratics with other leading coefficients, factor quadratics: special cases, factor by grouping, solve a quadratic equation using the zero product property, solve a quadratic equation by factoring, solve quadratic equations: word problems
That's quite a handful!
I have several videos on my channel regarding all of those. There are some in immediate sequence of another, some from certain textbooks (such as my Big Ideas Math run), etc. I could link you to some of those, but if you type some of those keywords in when searching for my channel you'll find the whole set of them!
ur da goat for this
Glad to hear that even a few years later people like you can always continue to be helped! You're welcome, as this video isn't going down any time soon! :)
Can we use completing the sqaure for question 1 and 2 to get vertex form and then find the y and x value? Thanks.
Yes, of course! I try and avoid using completing the square unless I have an even linear coefficient (after factoring out anything in front of my quadratic term). See that you get the same answer by doing that if you try. :)
hey! for the first question- how did you know to use -b over 2a??
-b/2a is the way to find the x value of any vertex for a quadratic equation written in standard form.
I don't suppose this comment section is the time to explain why this is the case, but if you know Calculus or look into the quadratic formula a bit you might see why this is true.
Just keep in mind that this video is teaching word problems for quadratic equations, so I'm somewhat assuming we know how to use certain things on quadratic equations when you enter the video, such as finding the vertex. :)
Thanks so much for asking!! Let me know if there is any other way I can help you!
my teacher wasn't here today, and wasnt here to explain the lesson; can you be my teacher instead?
Hahaha sure!
It’s too late for me my test is tomorrow, but do u have any quadratic word problem videos like this but with shapes
Hmm, do you mean like area/volume kinds of questions?
A couple of my recent videos had some problems out of the textbook for sure. I'll have to search far and wide for them, but anything from Chapters 2-4 where they have word problems on Modeling Mathematics may have something you're looking for!
amazing!
thank you
Anytime!
thank you so much
All in a day's work, sir!
Why we square the time, I know its quadratic function and t has to be square but why we multiply t by itself?
Where are you referring to this in particular?
If you mean with regard to the functions, yes time is being squared, but it is a model representing HEIGHT as a function of time. So the question as to why "time is squared" is answered by the fact that the height of the object is dependent on it.
Why does it depend on it? Gravity. Gravity is a force based upon acceleration, which means it expressed not how much an object changes position over time, but how much it changes velocity over time. Its units are not feet per second (ft/sec), but rather feet per second per second (ft/sec^2). This is what creates the parabolic arc of height (once again, due to gravity), and that occurs in the form of a quadratic model.
How did u get - 30 for problem 1 like where did you 30 from ? FOR "C"
After setting up my quadratic equation -16t^2 + 16t + 480 = 0, my personal plan for solving was by use of factoring and the zero-product property. My first step in factoring was seeking a greatest common factor (GCF), and that value happened to be a -16. That means that I can divide -16 among all of my terms, and what I wrote inside the parentheses is what each value becomes after that division:
-16 ( t^2 - t - 30 ) = 0
So, where does -30 come from? 480 divided by -16.
If you distribute that -16 back into all three terms, you will restore the original equation that we have set up, where -16 * -30 = 480 as well.
Hopefully that helps!
Sir are they are only called as situation probelms
Sure, I suppose!
jason is dead
😂🤣
R.I.P. Jason. You now serve as an academic lesson to the mathematical faithful! He was funny, sweet, and now quadratic.
very helpful, but in tests we dont have 15 minutes to spend on a question, it would be helpful if u would get to the point
Fair enough. I can speed run through these questions as well (I can finish this whole assignment in under ten minutes), but the point of *my* videos personally are to teach the material itself to cater to the lowest common denominator (those learning it for the first time). I can excuse that by saying that one who is watching can still speed up the video, scrub through it, fast-forward it, or skip it entirely. There are other TH-cam videos out there that have expedited versions, and mine tend to not be those. I do have videos like that here and there though, and you'll find them; of course, whenever I do make these, I'll have several students that say I go too fast and don't explain a step that they wanted.
In other words, I'm not doing the problems to teach the material (this is not what teachers SHOULD do with examples either). Instead, I am using the material to support what it is that I'm teaching. That way, when a student attacks a problem with some variations to it, they aren't completely dumbfounded because "it's not exactly like the last one but with different numbers." They have the luxury of opportunistically seeing more angles to it and they have a more general feel of what's happening. This is a conversational piece to give students an inner dialogue, particularly my students. I'm sure you know the Abraham Lincoln quote (which always changes the time around), saying something like: "If I had an hour to chop down a tree, I'd spend the first 45 minutes sharpening my axe." This video is mostly axe-sharpening, and then I chop away when I'm ready to go.
By the way, I'm not saying you're wrong on how I approach these. I'm just saying that this is an intentional stylistic approach that I choose to use. I agree, we don't have 15 minutes to spend on a problem. Thankfully, these problems aren't your test.
If you're interested in sending me a PDF of a word problem sheet that you have, I'll happily make a 15-20 minute version of a similar thing in contrast to this one though! :)
@@MrRobinsonsMathChannel Thank you so much for the offer and feedback, i understand what your trying to bring through these videos and its very much appreciated, My test is tomorrow therefore probably not enough time to make an explanation video
@@laraa7209 Understood! Let me know if you would like one all the same.
And, of course, good luck on your test!
Thanks
King
Hardly! I am flattered though haha.
thanks
pls i have a test tomorrow
Does this video help??
this is helpful but i’m so confused also, like as much as as i try to understand this topic it’s confusing 😭
Hi there, it depends on how you're entering this as a whole. If you don't know the background behind factoring, quadratic formula, completing the square, vertexes, etc. then it can definitely be a daunting task.
The purpose of this video was less on teaching how to do THOSE specific things (though I have videos on them if you want to hear more), but rather how to interpret the word problems as a whole. If you're still having trouble on the latter portion, I'm sorry that my video wasn't enough help on clarifying those portions.
why is #5 2.25 and not 6.75 ft?
Hmm, well I guess the bigger question is why would it be 6.75 feet? I showed where I calculated 2.25 feet from. I don't know how else I can explain "why it is what I calculated" outside of what I showed on the screen. I don't know where 6.75 feet comes from, or rather how a human jumps that high in the air to begin with haha.
Did you do 9/4 + 9/2? I believe the 9/4 is negative when you multiply -16 by the squared value. Maybe that's where you got 6.75 from.
It help I want video mpm2d grade 10 math of Quadratic equation
Sorry, I must've missed your comment when you first made it. It might be too late to take your request, but what were you asking for specifically?
Thank you so much Sir
Of course, Rovic!
you look like Niko Omilana
Hahaha never heard of him! Just looked him up, and I actually think one of my students from last year even looks much more like him, and I think he'd agree.
But hey, if it's a compliment, then I'll take it! If not... well... I hope the video helped you! 😆
Lets see if bro saved me...
(I'm cooked)
Time to start cookin'!
@@MrRobinsonsMathChannelThis is my alt account, and I’m reporting with good news! I got a 💯
@@iistormyx 100?? No way, sweet! Way to go, you earned it!!!
You’re a live saver, I’ll definitely be back for more!
@@iistormyx Well I haven't recorded anything about quadratics in a while, so I hope everything I've done so far is enough!
I hope i pass my math exam tomorrow 😭
Good luck!!!