`intsin^2x/2\ dx`

Explanation

`int sin ^{2} frac{x}{2} d x `

`=int(frac{1-cos x}{2}) d x[therefore sin ^{2} frac{x}{2}=frac{1-cos x}{2}] `

`=frac{1}{2} int(1-cos x) d x `

`=frac{1}{2}[x-sin x]+C`