# Finding value of sin(theta) from value of cos(theta).

• November 26th 2010, 07:46 PM
SOHCAHTOA
Finding value of sin(theta) from value of cos(theta).
I've been staring at this question...for so long.

if cos/theta = 1/3 , find the value of 6sin^2/theta - 6
• November 26th 2010, 07:47 PM
Prove It
Use the Pythagorean Identity:

$\displaystyle \sin^2{\theta} + \cos^2{\theta} = 1$.

Substitute $\displaystyle \cos{\theta}$ and then rearrange.
• November 26th 2010, 07:51 PM
SOHCAHTOA
Thanks for the tip!! :D