Video after video. Lesson after lesson. I could never understand what I was supposed to do. Until I watched your video. So simplistic and not a bunch of writing and lots of talking. Straight to the point. Thank you!
"Quite infuriating"? Man, you said it! I am a retired electrician who washed out of civil engineering because of calculus and specifically, trig identities. To this day, I have math books beside my bed, in the bathroom, in my car, etc. I really would like to get a grip on this stuff and it has turned into a kind of grudge match between the math and my little brain. I found your video very well presented -- not some guy scribbling illegibly at warp factor 9 -- and the content moves along at a rate where even an idiot like me can pause the screen and work through the material to catch up to you. Well done!
The problem discussed at 4:40 took me a while to solve, but once I began applying your strategies and recalled concepts from rational functions in algebra, everything started to click. Thank you for another great video, Professor Dave.
This cleared up quite a bit of questions! Can't ask questions in class not because my teacher doesnt let us, but because I don't like to hold the class back by asking questions to problems I should have figured out days ago
I haven't done this stuff in about 3 years. I very much remember this as being THE worst part of trig. I practically experienced flashbacks attempting these again. 😂 Anyway, love this entire series. It's an excellent refresher, and very well put together! Thank you!
let's do another because they are so fun! after that sentence i burst out laughing because i found it insanely ironic, made my day 10/10 even if it wasn't a joke
Thanks. My algebra 2 teacher glossed over the 3 basic identities so I couldn't really understand it. This video helped me more than 3 of her in class periods. Thanks!
You're a great teacher! Thank you so much, your video helped me a lot to understand this lesson. I hope that you'll continue to make videos on solving mathematical problems. 😊
Wish I had seen this last year. But now I still struggle with trig because of the new formulas like sin (x+y) and all those double and half angle formulas. Its been bothering me for a while and my boards are coming up. So, professor, can your next video be related to advanced trig functions. My notifications are on so I get informed everytime you upload. Thanks in advance
I’m probably weird for this, but I loved this part of Trigonometry. Everything else in trig was boring, or irritating but this was actually really fun 😂
sorry for the late response to this comment!!!!!! what he did was factor out what both sides of the subtraction side had, being the sinx, that is why there is now a 1 as well. This makes it easier to turn the (1-cos^2x) into the sin^2x
@@dilltHi, I am struggling with that question too, would that be possible for you to write it down because I still don't understand? sin x - sin x cos^2x = sin x/sinx - sinx/sinx • cos^2x ??
This is because if you calculate [sin(x)(1 - cos^2(x))] you will get exactly [sin(x) - sin(x)cos^2(x)]... then it is just a different way (though factor out both sin(x)) to represent the same thing... but now it will have the [1 - cos^2(x)] which can be converted to [sin^2(x)] that multiplied by the remaining [sin(x)] will give [sin^3(x)] on the left side. To end: [sin^3(x) = sin^3(x)]. It is the same as [a - ax] => a(1 - x).
Professor dave, I have watched all your educational videos and i affirm that your videos are much useful & informative but problem is that you have uploaded less video concerning math... I request please upload plenty of math lessons...
Since the video is a little old, you may not see this, but on the second example where you said multiplying cos x by cos x/cos x seemed arbitrary it looks more like cheating to make the process work. I'm 20 years out of school working through a trig unit for a home learning course so I can go to University and I see a lot of this kind of thing in my course material and none of it gets explained. How is it that you can do that without multiplying the other side of the equation as well? I know I probably look super dumb right now, but Maths is hard!
i was terrible at this in 10th grade. now in 12th- i have been academically inactive for 2 years and i got these in one go. maybe it was just the way it was taught and mindfulness back then!
At 2:11 why are you multiplying cos x? I understand you are setting up for a pythagorean identity but to me it just looks like you pulled cos x/cos x out of thin air.
I like the subtle comprehension tests. Sadly, i can't seem to comprehend the majority of this chapter. A bit frustrating seeing how important this is for calculus. I think im having such trouble because its highly focused on vocabulary turned equation. Im pretty sure my left temporal lobectamy amplifies the difficultly. Seeing as how that is where we keep our vocabulary.
"how about one more since these are so fun" Dead
Video after video. Lesson after lesson. I could never understand what I was supposed to do. Until I watched your video. So simplistic and not a bunch of writing and lots of talking. Straight to the point. Thank you!
"Quite infuriating"? Man, you said it! I am a retired electrician who washed out of civil engineering because of calculus and specifically, trig identities. To this day, I have math books beside my bed, in the bathroom, in my car, etc. I really would like to get a grip on this stuff and it has turned into a kind of grudge match between the math and my little brain. I found your video very well presented -- not some guy scribbling illegibly at warp factor 9 -- and the content moves along at a rate where even an idiot like me can pause the screen and work through the material to catch up to you. Well done!
You are describing me. 😂👍
I’m about to fail tf out this test....
same
@@VeldyR6 YOOOOOOO SAME HERE
@@tenzshed6026 test tmr, did you fail?
@@matthewgoldberg6341 test tmrw lmao. how'd you do.
SAMEE
"since these are just so fun," says it so unenthusiastically. but on a serious note, this really helped
haha i do actually think they are fun
The problem discussed at 4:40 took me a while to solve, but once I began applying your strategies and recalled concepts from rational functions in algebra, everything started to click. Thank you for another great video, Professor Dave.
This cleared up quite a bit of questions! Can't ask questions in class not because my teacher doesnt let us, but because I don't like to hold the class back by asking questions to problems I should have figured out days ago
I haven't done this stuff in about 3 years. I very much remember this as being THE worst part of trig. I practically experienced flashbacks attempting these again. 😂
Anyway, love this entire series. It's an excellent refresher, and very well put together! Thank you!
ifkr! bruh i know absolutely everything else in like the entirety of math except this shit
Thank you Prof Dave, came here cause I wasn't sure what to do when some terms are squared and some aren't. This stuff is pretty satisfying to solve
10 minutes before my test: well idk what im doing
let's do another because they are so fun! after that sentence i burst out laughing because i found it insanely ironic, made my day 10/10 even if it wasn't a joke
Thank you Professor Dave-- I used to think these were so frustrating, but now I think they're beautiful :)
Mason Tipton NERD!!!
Dave Grohl is helping me pass my midterm. Thanks!
This man cooked so much in this video, and I am so cooked in this test
Thanks. My algebra 2 teacher glossed over the 3 basic identities so I couldn't really understand it. This video helped me more than 3 of her in class periods. Thanks!
0:03 i seriously love this part 🤣🤣🤣
now I'm a bit confident abt trigonometry..........thanks, professor!!!
at 2:30 dont you have to multiply both sides by cos/cos. what rule says you can selectively manipulate on part like that?
oh nvm that cos/cos is considered 1
You're a great teacher! Thank you so much, your video helped me a lot to understand this lesson. I hope that you'll continue to make videos on solving mathematical problems. 😊
Wish I had seen this last year. But now I still struggle with trig because of the new formulas like sin (x+y) and all those double and half angle formulas. Its been bothering me for a while and my boards are coming up. So, professor, can your next video be related to advanced trig functions. My notifications are on so I get informed everytime you upload. Thanks in advance
in fact that's exactly what the next clip is about!
I’m probably weird for this, but I loved this part of Trigonometry. Everything else in trig was boring, or irritating but this was actually really fun 😂
yes indeed u are weird... proving geometry is easier than this for me
Probably one of the best intros in the history of intros
Imagine the world without this man😂
Thanks this made me feel better after my test.
in the checking comprehesion section, the last equation went from
sin x - (sin x)(cos² x)
to sin x - (1 - cos² x)
may I ask how and why?
sorry for the late response to this comment!!!!!! what he did was factor out what both sides of the subtraction side had, being the sinx, that is why there is now a 1 as well. This makes it easier to turn the (1-cos^2x) into the sin^2x
@@dilltHi, I am struggling with that question too, would that be possible for you to write it down because I still don't understand?
sin x - sin x cos^2x =
sin x/sinx - sinx/sinx • cos^2x ??
This is because if you calculate [sin(x)(1 - cos^2(x))] you will get exactly [sin(x) - sin(x)cos^2(x)]... then it is just a different way (though factor out both sin(x)) to represent the same thing... but now it will have the [1 - cos^2(x)] which can be converted to [sin^2(x)] that multiplied by the remaining [sin(x)] will give [sin^3(x)] on the left side. To end: [sin^3(x) = sin^3(x)]. It is the same as [a - ax] => a(1 - x).
5:30 Aren't we supposed to multiply both sides of the equation by 1-sin x/1-sinx? or am i missing something here?
I think it's because anything over itself is 1, so he doesn't show it because it's just saying 2secx(1), and (1-sinx)/(1-sinx)=1
Professor dave, I have watched all your educational videos and i affirm that your videos are much useful & informative but problem is that you have uploaded less video concerning math...
I request please upload plenty of math lessons...
buddy i upload two maths a week! don't worry, you will get all of your math. i'm shooting more next week.
@@ProfessorDaveExplains
I don't know if you make videos about calculus or not but it would be of great help for me cuz I suck at calculus
I have a 35 part series on calculus, check it out!
Thank u so much it helps me a lot in my trigonometry
you make it look so easy.thank you prf.dave
You are right . .......Please do logarithmic derivatives
Since the video is a little old, you may not see this, but on the second example where you said multiplying cos x by cos x/cos x seemed arbitrary it looks more like cheating to make the process work. I'm 20 years out of school working through a trig unit for a home learning course so I can go to University and I see a lot of this kind of thing in my course material and none of it gets explained. How is it that you can do that without multiplying the other side of the equation as well? I know I probably look super dumb right now, but Maths is hard!
You can multiply anything by 1 without changing its value, and anything over itself equals one.
@@ProfessorDaveExplains Wow, that was fast. Thank you and I now feel super dumb because that is so obvious.💪🧠
@@ProfessorDaveExplains I was wondering the same but yes right that makes sense! Cool thanks professor
I literally have finals tmr I'm hopeing I'll get Tru this
how did they turn out?
@@mechagear4819 Passed! :)
Daniel S good job
This video helped me a lot. Thx
With this video, I ain't failing the test no more
i was terrible at this in 10th grade. now in 12th- i have been academically inactive for 2 years and i got these in one go. maybe it was just the way it was taught and mindfulness back then!
Man! There are so many relations between the different functions.
Thanks! You made this extremely easy!
Thank you so much for this video!!! you're helping me understand trig identities much better than my teacher.
Plz prof Dave prepare us the concept of mirage of total internal reflection I haven't enough idea tnx
Professor Dave, I would like to know why is Trigonometry so hard; even through you have look at the same series of problems for days?
Where does this other cosx come from?
At 2:11 why are you multiplying cos x? I understand you are setting up for a pythagorean identity but to me it just looks like you pulled cos x/cos x out of thin air.
common denominator tingz
you are my hero!
Genius Dave
I thought when you multiply fractions you have to take the reciprocal of tan x. So wouldn’t that be cos x over sin x ?
that is the reciprocal of tan but i'm not sure what the question is
Sir doubt at 5:35 ,we can take lcm also but why we have not taken ? And how to know
We can do that as well, in fact my school teacher did took LCM for this identity but this way is a lot quicker than that one.
Simply amazing. I love how you lecture and utilize graphics, thank you, Prof. Dave!
I like the subtle comprehension tests. Sadly, i can't seem to comprehend the majority of this chapter. A bit frustrating seeing how important this is for calculus. I think im having such trouble because its highly focused on vocabulary turned equation. Im pretty sure my left temporal lobectamy amplifies the difficultly. Seeing as how that is where we keep our vocabulary.
Is that a rule of trig when you multiplied cosx times cosx/cosx? Are you allowed to pull out that fraction when necessary?
well you can always multiply anything by 1
@@ProfessorDaveExplains ohhhhh I see how cosx/cosx= 1, in that case yea I see how you can multiply anything by 1. Thank you a lot
At least a thousand times better than my Math teacher and he did it in minutes
He explains it very well
Thanks professor Dave ldk what to do but u made it simple
7:59
Thank you Professor
Thanks for everything I have a question where did you get the 1 how did it change by sine on the second exercise,the one in the middle bottom
sorry i'm not sure what you're referring to.
@@ProfessorDaveExplains on checking comprehension. I didn't understand the one in the middle in where you replace the - sine by 1
ah i see, so i factored sinx out of that difference.
@3:43 -- isn't that a Pythagorean Identity in and of itself?
yep! just proving it
In min 6:10 Why "2 sec X = 2 / cos X"
Oh I see why, "sec X = 1 / cos X"
Thanks professor, Happy Birthday.😁😅😫
I LOOOOOVE YOU FOR GOD SAKE THANK YOU SO MUCH YOU SAVED ME FROM MY USELESS TEACHER
You will never understand how much your videos have helped me, you’ve literally saved me from killing myself
في عرب هون
العرب في أي مكان
thank you so much for helping me with my stupid math homework ahhhhhh!!!!!
Is it really true ? What about x = kπ , where k in Z
Now I'm ready for my test tomorrow
6:17 "since these are just 'sooo' fun"
why does it sound like even he is admitting these are not fun XD
haha i guess it does come off sounding a little sarcastic but i do genuinely think these are super fun!
Lmao
LMAO
Sir instead of using trig formula to solve the problem can we use this strategy? Pls reply
sorry i don't understand the question
@@ProfessorDaveExplains Sir how can i contact you to ask my doubts?
email is best
thanks
I'm not all the way there yet but at least I'm not just staring at the paper anymore so thank you 🙏
I wish u were there when I was in 10th std.trignometry was my nightmare.But it's kk I still need them.
cheers professor ur like some god of maths or something, ty
Excellent video
Even Speedwagon understands.
Ambulance
He does?
*_Niiiiiiiiiceu_*
There’s one thats like TanA= secA/cscA
Help?😞
convert them into sines and cosines and it'll become clear
Goddamit this. Trig identities is the hell of my life
watching this right before my test pls pray for me
thaaaank yoooouuuu veeerryyyy muuuccccchhh!
in the third question in the comprehension it need to be a plus rather than minus i think
Done.
Im failed many times but im never give up then my 3rd try its correct
Wow, you know a lot about all kinds of stuff, KONNOO DIIOO DAA!!!!, understands.
Reviewing for semestral test 😭😭
Reall
Farquad be teaching math now
It looks so easy now
Why is this way easier than graphing trig functions for me ☠️
Thanks it is cool
awesome video
my brain is not braining
Hi professor!
hello!
Professor Dave Explains I'm glad you replied! Your channel helps me a lot with school! Thank you!
I find the writings highlighted in black quite irritating
too sleepy to learn
I’m legitimately cooked how am I supposed to remember allat
I’m not very smart so this is hard asf
this is class 10 level right? i was searching for class 12 🥲
How many of you all just see the working and don't do them themselves....ha ha ah ah a..Welcome to the group...
Found the content helpful, but it didn't really help me with the practice problems at the end.
Anybody else stuck doing trig in quarantine?
That easiest questions I never see on tri ident...
It made sense up until the second example...imma fail this test
Jesus has saved my CA again 👏👏👏
i like the tutorial
I dig the chest hair
Reveal your ethnicity, Professor Dave! You look like a Cuban Einstein.
haha that's a new one! check out "ask professor dave #1"
Professor Dave Explains I will! I can’t believe I received such a timely response. You’re the reason I have a 105% in Pre-Calculus.
👍👍👍👍👍👍👍👍
Bagsak nako bukas