Revision12321
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Help and advice on how to learn the values for sin cos and tan up to 360°
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Infinite Series
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(Original post by Revision12321)
Help and advice on how to learn the values for sin cos and tan up to 360°
Aren't all of the maths exams calculator papers? If so, you don't need to learn these values as you can simply type them into your calculator and get results within a second.
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mqb2766
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(Original post by Revision12321)
Help and advice on how to learn the values for sin cos and tan up to 360°
You really just need 0..90 and then the CAST diagram knowledge.

Three things that may help for learning the 0..90 values

1) Remember cos(90-x) = sin(x) so cos(60) = sin(30) etc

2) Think about them as right angled triangles triangles so you can get 30 & 60 by splitting a equilateral triangle in two. The sides of one of the 30-60-90 triangle are in the ratio
1/2 : sqrt(3)/2 : 1 or
1 : sqrt(3) : 2
which are your cos, sin & tan of 30, 60.
Similarly for a right angled isosceles triangle with angles 45, 45 & 90. The sides are in the ratios
1/sqrt(2) : 1/sqrt(2) : 1 or
1 : 1 : sqrt(2).
That gives sin, cos & tan for 45.

3) For memorizing, the hand method
https://www.youtube.com/watch?v=PF2nmCVSUEs
http://www.mrbartonmaths.com/blog/re...ometry-ratios/

TBH, the second point takes a bit of thinking about, but often when you do understand it, its easy to recreate the values if/when you forget.
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Revision12321
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(Original post by mqb2766)
You really just need 0..90 and then the CAST diagram knowledge.

Three things that may help for learning the 0..90 values

1) Remember cos(90-x) = sin(x) so cos(60) = sin(30) etc

2) Think about them as right angled triangles triangles so you can get 30 & 60 by splitting a equilateral triangle in two. The sides of one of the 30-60-90 triangle are in the ratio
1/2 : sqrt(3)/2 : 1 or
1 : sqrt(3) : 2
which are your cos, sin & tan of 30, 60.
Similarly for a right angled isosceles triangle with angles 45, 45 & 90. The sides are in the ratios
1/sqrt(2) : 1/sqrt(2) : 1 or
1 : 1 : sqrt(2).
That gives sin, cos & tan for 45.

3) For memorizing, the hand method
https://www.youtube.com/watch?v=PF2nmCVSUEs
http://www.mrbartonmaths.com/blog/re...ometry-ratios/

TBH, the second point takes a bit of thinking about, but often when you do understand it, its easy to recreate the values if/when you forget.
Thank you not sure I understand what you mean for the second method but thanks
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username3973192
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(Original post by Revision12321)
Help and advice on how to learn the values for sin cos and tan up to 360°
Hey!

Here's a vid i used when I was learning it:
https://www.youtube.com/watch?v=PF2nmCVSUEs

Hope this helps!
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mqb2766
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(Original post by Revision12321)
Thank you not sure I understand what you mean for the second method but thanks
https://www.khanacademy.org/math/tri...cial-triangles
https://www.youtube.com/watch?v=nVTtSE5nv7c

Explaiin the special triangles - trig values in more detail.
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Revision12321
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(Original post by thestudent33)
Hey!

Here's a vid i used when I was learning it:
https://www.youtube.com/watch?v=PF2nmCVSUEs

Hope this helps!
Thank you so much this helps loads !!!!
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username3973192
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No problem
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