Question

how to find sin315 on the unit circle

Answer 1

http://www.geocities.ws/petrinamaher/UnitCircle.GIF <--- a better Unit Circle

Answer 2

On the unit circle sin will always be the y coordinate divided by the x coordinate.
Use Joe's unit circle to get the appropriate values to get your answer.

Answer 3

then how would you do the cos 225 do you put it into a calculator thats where I get messed up on

Answer 4

Find 225 degrees on the unit circle. x = cos and y = sin