posted by Bailey .
if cosx equals square root 3 over 2, find sinx
cosx = √3/2
and we know that the cosine is positive in quadrants I and IV
I also know that cos 30° or cos π/6 = √3/2
so x = 30° or 330° OR π/6 , 11π/6 in radians
then sinx = 1/2
sinx = -1/2 (because the sine is negative in IV)