trig
posted by Denise .
If cscx=2 and x greater 90 degrees and x less than 180 degrees, then sin x/2 =

So sinx = 1/2 and x must be in 2nd quadrant.
then by Pythagoras cos x = √3/2
we know cos 2A = 1  2sin^2A
then cosx = 1  2sin^2(x/2)
√3/2 = 1  2sin^2(x/2)
2sin^2(x/2) = 1 + √3/2
sin^2(x/2) = (2 + √3)/4
sin(x/2) = (√(2+√3))/2