I haven't done this in over 20 years and my nephew asked me for help with his school work so I had a snoop about the internet. This was the most helpful. I think you would do well to briefly explain why the cast diagram is positive or negative for the trig functions at the beginning. ie why there is more than one solution. But as an explanation of method it was succinct and straightforward. Thank you.
I got an exam tomorrow and I've been panicking for a while now trying to figure out the CAST diagram and you've just saved me! This video is so helpful thank you!
thanks so much for this video. I am a missionary helping children in high school and i have done this in such a long time. It really helped to explain and make it clear really quickly. God bless you
Thank you so much...........I can't explain how much you helped me through these videos. My confidence came back after watching these lessons. Such a great revision.Thank you again. God bless you.
For tan(2x+30)=1.2, are there not supposed to be 4 values? The others being 190.1 and 280.1 And for sin(3x-10)=-0.8, I think you are missing 201.03, 225.6, 321.01 and 345.03 Please clarify whether this is the case as I am sort of confused. Thanks.
yeah i believe thats right as well, i think shes forgot about the 2/3 theta which means that we should double our range because the answers are being divided by 2
love your videos ♡♡ honestly I really find your videos helpful. my previous maths teacher moved schools and I have been struggling as I found it hard to adapt to my new teacher. Your teaching style is versatile and helps me and my classmates alot. I do hope you'll be able to post more math videos! It helps us alot through AS and hopefully A2. Unfortunately we're all students and dont have the capacity to contribute to your patron page 😭 However, we do contribute by views and likes! Hope that helps you out
@12 mins u say there is no point doing sin Q ? can it be done though so as in you only get the positive solutions on first CAST diagram but no sol on other one ? thanks
I have a question at 15:08, the range was till 720 degrees, and you added 360 to both your answers, i wanted to ask that is there a specific reason why we added 360 to them, and also if the range is 1080 degrees (3 cycles) so will we add 720 to both our answers in that case?
@@StarfishMaths it defenetly does. I wonder if you have a video explaining why the cast rule works. Like why is sin only positive in the first and second quadrant.
@@juanjosetalerogarcia902 I don't have a whole video on that, but you can investigate it with the graphs. Draw out the sin graph for example, and you'll see where it's positive (above the x axis - first and second quadrants). Quite a nice thing to do actually so you can feel more comfortable with what the CAST is representing.
What a great video, thanks very much. I'm going to set it as a HW for my year 13 class to watch for revision. However they are going to spot your deliberate mistake in the last two questions (I hope), since you were solving for tan(2x + 30), not just tan x, and sin (3x + 10), not just sin x.
For the 3rd example at the end of the video, isn’t that wrong? As the angle is 2x+30 wouldn’t you sub 360 as x to find the range of values to be found. Then you keep on adding 180 until you get to 750, then you solve.
Thank you really good video. I am just a bit confused with the last two questions. I think you are supposed to change the range to get more solutions. I have 4 solutions and 6 solutions for the last two questions.
She might be making it easier for people to DO but not understand. Anyone who doesn't question why the negative is being ignored hasn't understood and anyone who does question it won't be helped by this video.
I don't understand the last question because the trig ratio is sin, which is positive in both the acute and sin quadrant, yet you used cos. Could you please explain? Thank you
If you had something like 5 sin x = 1+2 cos^2 x How would u would the last bit out, like I understand how to do the but before the = but unsure how I would start the part after the = thank you
Great video but I'm confused for the last question as I solved for x which gave me 21 (instead finding out 233.1 and 306.9) and I put 21 degrees on cast diagram and got solutions x=201 and x 339, the confusing part is 201 is a valid solution but 339 is not, could you clear up what has happened here. Thanks
you explained the purpose of the CAST diagram really well. My teacher didn't even bother with that. Thanks very much!
Oh excellent glad you found it useful
ong fr🤌🤌🤌
I haven't done this in over 20 years and my nephew asked me for help with his school work so I had a snoop about the internet. This was the most helpful. I think you would do well to briefly explain why the cast diagram is positive or negative for the trig functions at the beginning. ie why there is more than one solution. But as an explanation of method it was succinct and straightforward. Thank you.
Thanks lad I hope judes ok
I got an exam tomorrow and I've been panicking for a while now trying to figure out the CAST diagram and you've just saved me! This video is so helpful thank you!
Ah-ah this is sooooo good for revision!!! I feel my confidence back again :D
Thanks so much I was struggling so much with this but suddenly everything made sense even just a few minutes into the video!
I haven't understood this all year then I watched your video and I now understand perfectly. Thank you SO much
thanks so much for this video. I am a missionary helping children in high school and i have done this in such a long time. It really helped to explain and make it clear really quickly. God bless you
Damn.. you've helped me alot! Looking forward to more content :D
Karan Jason Glad you found it helpful! Best wishes
This is the most helpful trig video I have found on tri equations and ASTC. Thank you so much.
thank you so much!! it is currently the night before my pre mock and this helped so much!!
This was the most helpful.
wow this is really helpful its also great for further maths in engineering too! cheers
Hey Sarah, u really helped my younger brother out with his college course ( he has a chronic disease). Much appreciated
Glad to hear it helped. Best wishes
Omg this is such a underrated channel, this actually explains things well
Thank you so very much for doing all of this explanation, you made my life in mathematics easier with CAST diagrams💯
it's 2020 and your video has really helped me. Thank you
Finally I understand this after two years.Thanks.
Angela Kenneth that’s wonderful, glad it was helpful
11:10 why only A even C will be positive right!!??
Thank you so much...........I can't explain how much you helped me through these videos. My confidence came back after watching these lessons. Such a great revision.Thank you again. God bless you.
Just didn't understand the thing with negative range -180 < x < 180
For tan(2x+30)=1.2, are there not supposed to be 4 values? The others being 190.1 and 280.1
And for sin(3x-10)=-0.8, I think you are missing 201.03, 225.6, 321.01 and 345.03
Please clarify whether this is the case as I am sort of confused. Thanks.
yeah i believe thats right as well, i think shes forgot about the 2/3 theta which means that we should double our range because the answers are being divided by 2
Sam Madders You don’t have to fiddle with the range, that makes it more complicated imo, but sure.
@@pickledirick8338 i guess, but i just like to make it bigger then divide
You're right, she is missing LOTS of solutions! Oh dear, bit of a fail of a video...
You explained this much better than my text book, thank you.
its good to be taught by someone beautiful, it makes maths amazing, THANK YOU very helpful
love your videos ♡♡ honestly I really find your videos helpful. my previous maths teacher moved schools and I have been struggling as I found it hard to adapt to my new teacher. Your teaching style is versatile and helps me and my classmates alot. I do hope you'll be able to post more math videos! It helps us alot through AS and hopefully A2. Unfortunately we're all students and dont have the capacity to contribute to your patron page 😭 However, we do contribute by views and likes! Hope that helps you out
A very big thankyou to starfish maths 😊
Wow thank you so much you are the only person who has made me understand this!
@12 mins u say there is no point doing sin Q ?
can it be done though so as in you only get the positive solutions on first CAST diagram but no sol on other one ?
thanks
Thank you very much you saved my day, l had previously skipped the topic in my maths class as textbook examples were confusing.
absolute legend - thanks
I have a question at 15:08, the range was till 720 degrees, and you added 360 to both your answers, i wanted to ask that is there a specific reason why we added 360 to them, and also if the range is 1080 degrees (3 cycles) so will we add 720 to both our answers in that case?
Your lesson really helped me during my trig crisis...thank you so much😁😁 you're so smart😁
Ah excellent glad to hear it!
You are absolutely amazing! I finally understand this topic. Thank you so so much!
OMG thankyou so much❤️ I finally understand this now
So glad to hear that!
I really enjoyed your lesson. Thanks 🥰
Thanks alot.... Now I really understand trig.. equations......I guess My teacher didn't me everything I really needed to know
I've always struggled with the cast rule, but now i understand it. Thankssss
So glad it made sense!
@@StarfishMaths it defenetly does. I wonder if you have a video explaining why the cast rule works. Like why is sin only positive in the first and second quadrant.
@@juanjosetalerogarcia902 I don't have a whole video on that, but you can investigate it with the graphs. Draw out the sin graph for example, and you'll see where it's positive (above the x axis - first and second quadrants). Quite a nice thing to do actually so you can feel more comfortable with what the CAST is representing.
@@StarfishMaths that makes so much sense thanks 😃
So much better than my teachers
Thank you for literally saving my exams
What a great video, thanks very much.
I'm going to set it as a HW for my year 13 class to watch for revision.
However they are going to spot your deliberate mistake in the last two questions (I hope), since you were solving for tan(2x + 30), not just tan x, and sin (3x + 10), not just sin x.
She did solve it for tan x - just did after finding the angles, not before.
@@cheesecake2281 they mean because they should’ve gotten more than 2 solutions
Thank you this video has clarified my misunderstandings on trig
16:40
Does the one in the bottom left not have 4 solutions?
Thanks, the ones that are harder than this are so tricky
Thanks a lot for your online math lessons they really help us understand some topics very well please continue launching more lessons online.
will it always be an acute angle?
For the 3rd example at the end of the video, isn’t that wrong? As the angle is 2x+30 wouldn’t you sub 360 as x to find the range of values to be found. Then you keep on adding 180 until you get to 750, then you solve.
Wow ! Thank you so much, I was struggling but this has really helped me understand
Love your lectures
Imagine getting a heart from starfish Maths plz
Thank you so much! This video helped me out quite efficiently with my a-level homework!
Thank you really good video. I am just a bit confused with the last two questions. I think you are supposed to change the range to get more solutions. I have 4 solutions and 6 solutions for the last two questions.
You are the best. PERIOD‼️
Thank you for your videos, very helpful.
i LOVE YOU❤❤❤ THANK YOU SO MUCH MAAM❤❤❤❤❤❤❤❤❤❤❤❤❤
Thank you so much for your teachings
THANKS A LOT FOR YOUR HELP, I totally understood everything and it helped me out so much. Thanks again!
At 6:17 why are they the only two solutions if it goes up to 360? Can someone explain that please? :)
Finally, this starts to make sense. Cheers gorgeous
Plamen Savchev weirdo
Hi Starfish Maths, I wanted to get in touch to ask whether I could link to or embed some of your videos on my website? Thanks, James.
Of course! Glad they can be of help.
Your website looks fantastic, I look forward to trying it out with my students!
You are a force to be reckoned with
I love your videos!
Im confused at 11:45 , why is that cast diagram is -90 on the bottom, shouldnt it be on top
me watching this walking to school when i have a test first lesson
You have enlightened me thank you so much 😊
David Kim Awesome thank you!
Thank u soOoOOo muchHhhh !!!!! It totally helped me out 😭❤️
there are no negative questions and im stuck on one
AMAZING... well-explained nd i like how u add extra tips nd background info!
This really helped out. Thank you so much!!
why did you add the values of tan in 7:30.
Because the tan value is positive in that quadrant which is from 180 to 270 so u add 180 to the acute angle
can you please make a video about sequences and series.
Thank you so much. This was so helpful. I'm going to share with others. I'll find the patreon link, too.
Thank you for the wonderful explanation!
Could you do a video explaining kinematics please?
is there a set number of solutions your supposed to get or does it just depend on the question?
You just saved my coronavirus maths mock
Phew!
Ugh, why ignore the negative in -0.2? Just do inverse sine of -0.2, get -11.5. It's a solution! Then work out whether it's in your desired range.
You realise she is making it easier for people to understand
She might be making it easier for people to DO but not understand. Anyone who doesn't question why the negative is being ignored hasn't understood and anyone who does question it won't be helped by this video.
@@1violalass true
Very well explained
You're the best
Thank you so much for the help 💖💖💖
Goodness me, I actually cried lol, this is amazing 👏
Sarah thank you so much for this video. It has helped a lot and again thank you. Now i know i am going to nail it on my test lol
Amazing video, thank you so much!!!
For the last question you did on sin (3x-10) why didn’t you use S and A to find outputs
thank you for the video! absolutely smashed it! how would you work out tan ^2(squared)x=3
hey what about if then angle is 0, 180, 270 or 360?
I don't understand the last question because the trig ratio is sin, which is positive in both the acute and sin quadrant, yet you used cos. Could you please explain? Thank you
If you had something like 5 sin x = 1+2 cos^2 x
How would u would the last bit out, like I understand how to do the but before the = but unsure how I would start the part after the = thank you
Also Amazing video
i finally understnd thank u sm
I think there is one more solution to the last question which is 201.03?
I come back to this video every time I have an exam
Are u from SA
Hello SA we approve
I will pass my exam on this thank you
how to find angle when it is 3cox2x
For tan (2x+30) and sin(3x-10) the answers are incomplete. You didn’t change the range because our x has changed.
Yeh, I saw that aswell, I thought I was going crazy yk
How do you solve this type of equation 2 tan feta= -3 for 0 degrees
Divide both sides by 2 to get tan theta = -3/2
This helped so much ,thank you❤️
Thanks for the valuable informations
very well explained Thank you
Thank you so much 🎉
Great video but I'm confused for the last question as I solved for x which gave me 21 (instead finding out 233.1 and 306.9) and I put 21 degrees on cast diagram and got solutions x=201 and x 339, the confusing part is 201 is a valid solution but 339 is not, could you clear up what has happened here. Thanks
Why is tan positive
Thank you so much ma'am