#1

For some reason I'm doubting the correctness of this, considering the redundancy in my homework, but cos(2*theta) = sin(2*theta) when theta is equal to pi/8 + pi(n), correct?

*Last edited by lespaulrocks39 at Nov 9, 2007,*

#2

...?

why is this in the electric guitar forum? haha

should move it to the pit soon before you get reported...

why is this in the electric guitar forum? haha

should move it to the pit soon before you get reported...

#3

Are those cos^2 and sin^2 or 2*cos, 2*sin?

#4

Lol, I "thought" I posted this in the pit, but I can't figure out how to move the thread...

But it is cos2* and sin2* fyi...

But it is cos2* and sin2* fyi...

#5

moved.

#6

Ahhhh!

#7

My brain hurts after reading that. I try to avoid maths where possible. Maths at 2.30 am is not a good thing.

#8

For some reason I'm doubting the correctness of this, considering the redundancy in my homework, but cos(2*theta) = sin(2*theta) when theta is equal to pi/8 + pi(n), correct?

If cos squared theta = sin squared theta then theta= pi(n) plus or minus pi/4.

cos^2 theta - sin^2 theta = 0

1 - sin^2 theta - sin^2 theta = 0

2sin^2 theta = 1

sin theta = (+)(-) 1/(sqrt 2)

theta = 45, 135, etc.

=180n (+)(-) 45

=pi(n) (+)(-) pi/4

Edit: v Oops, sorry. Well I don't really have any idea how to do the other one.

*Last edited by Yamiyo at Nov 9, 2007,*

#9

It's actually cos(2 TIMES theta) NOT SQUARED, hence the lack of a carat symbol.

Upon looking at it again, it is correct, because for cos(theta) = sin(theta), it would have to be pi/4 + pi(n), so for cos(2*theta) = sin(2*theta), it would need to be pi/8 + pi(n).

Upon looking at it again, it is correct, because for cos(theta) = sin(theta), it would have to be pi/4 + pi(n), so for cos(2*theta) = sin(2*theta), it would need to be pi/8 + pi(n).

#10

My brain hurts after reading that. I try to avoid maths where possible. Maths at 2.30 am is not a good thing.

Maths at any time is not a good thing!!

English Extension 2 FTW!!

#11

I found some code that does what you are asking (I think)...

printf("cos(2*theta) = %f, sin(2 * theta) = %f\n", cos(2*theta), sin(2*theta));

Course, it's been some 12 years since I touched that so take it for what it is worth.

Chris

printf("cos(2*theta) = %f, sin(2 * theta) = %f\n", cos(2*theta), sin(2*theta));

Course, it's been some 12 years since I touched that so take it for what it is worth.

Chris