## anonymous one year ago Help plsss

1. anonymous

Angle $\theta$ is in quadrant II and $\sin \theta = 5/13$. Determine an exact value for $\cos2 \theta$

2. arindameducationusc

easy....

3. arindameducationusc

use cos2theta=1-2sin^2theta

4. arindameducationusc

so, 1-2(5/13)^2

5. arindameducationusc

I hope you can get the answer now

6. anonymous

=p umm thanks?

7. arindameducationusc

My pleasure.... :)

8. anonymous

o wait isn't it supposed to be 1-2(12/13)^2?

9. anonymous

and then you get a final answer of 119/169