`int_(0)^(pi)(sin^(2).(x)/(2)-cos^(2),(x)/(2))dx`

Explanation

`int_(0)^(pi)(sin^(2).(x)/(2)-cos^(2).(x)/(2))dx`
`=-int_(0)^(pi)(cos^(2).(x)/(2)-sin^(2).(x)/(2))dx=-int_(0)^(pi)cos x dx`
`=-[sinx]_(0)^(pi)=-[sinpi-sin0]=0`