Find the value of `sin(1/2cot^(-1)(-3/4))`

Explanation

Let `cos^(-1) (-3//4) = theta`
or `cos theta = -3//4`
`rArr theta in (pi//2, pi)`
`rArr cos theta = -3//5`
`rArr 1 - 2 sin^(2) (theta//2) = - 3//5`
`:. Sin^(2) theta//2 = 4//5 " or " sin theta//2 = 2 sqrt5`