Please tell me I know sin2A, how to find Sin^2A, I don't know cosA or A?

Question

Please tell me I know sin2A, how to find Sin^2A, I don't know cosA or A?

Answer 1

sin^2A = (1 - cos2A)/2

cos2A = sqrt(1 - sin^2 2A)

Thus, sin^2 A = (1 - sqrt(1 - sin^2 2A))/2

There are 2 possible solutions (the sqrt can be +-)

Answer 2

So to compute something like

   2
sin (30 degrees)

you would compute the sine of 30 degrees, and then square the result.

The common interpretation of cos^2(30) is (cos(30))^2.

Does this help?