i want to find sin^2(3)

jboy314 has assumed that you meant this to be 3degrees.

When no units are mentioned it is usually assumed that the units are radians.

did you mean 3 degrees or 3 radians?

First recognize that this is the same as (sin(3))^2 so if you know what sin(3) is you just have to square it.  After typing it in a calculator i see that sin(3) is about 0.05244596

 

Typing in (sin(3))^2 i get .002739