Analytic Trigonometry help...

Hi,

Today we started working on what our book calls, Analytic Trigonometry. I am quite lost as to how I solve these problems. My college has a "Math Lab," but they were extremely busy when I went during my break between classes. I wasn't able to get any help there before I had to take off for my next class.

The first is (I will post some more after I figure this out if I still need the help):

2sin^2 theta -1 = 0

So I add one to the RS and divide by two leaving me with...

sin^2 theta = 1/2

Then I take the sqrt of both sides and get:

sin theta = 1/sqrt(2).

That is where I am lost. On some of the problems I am able to look at the unit circle to find the answer I am looking for, but what is 1/sqrt(2) on the unit circle? Some are simple, like the sin of sqrt of 1/2...

Then after I find that number I always seem to have issues getting the points. In this case I would draw the sin curve and put a line at 1/2.

Thanks in advance for the help! It is greatly appreciated!

-Tom