# Math Help - Trig

1. ## Trig

Determine the angle(s) for the following in the interval from 0-360 degrees. costheta=-0.363.

2. Originally Posted by rmweeks
Determine the angle(s) for the following in the interval from 0-360 degrees. costheta=-0.363.
If $\cos \theta = -0.363$

$\Rightarrow \theta = \cos^{-1}(-0.363)$

$\Rightarrow \theta \approx 111.285^{\circ}$

this angle is in the second quadrant. another is in the third, using reference angles, we find the other angle to be $\approx 248.715$

i rounded off a lot, so these answers might not be as accurate as you want them. try to understand what i did and redo the problem with more decimal places if you like