Solving a relatively easy trig. equation...

Hi!

The equation is...

$\displaystyle 2cos^2\Theta=2+sin^2\Theta$

i'm trying to solve for theta, limiting domain from 0 to 360 degrees.

After substituting $\displaystyle 1-sin^2\Theta$ for $\displaystyle cos^2\Theta$ and simplifying i ended up with...

$\displaystyle -3sin^2\Theta=0$ OR $\displaystyle sin\Theta=\sqrt0$

after applying arcsine i came up with an answer of 0 degrees. Now, my graphing calculator of course does not provide ALL possible answers. I noticed that 180 degrees is also an answer. I guess this is because of the theoretical -0 degrees that when squared would result in 0 too?

Did i do this correctly?