∫−ππ1+cos2y2y(1+siny)dy
(=\underset{\text{(Odd)}}{\int_{-\pi}^\pi \frac{2 y}{1+\cos ^2 y} d y}+\underset{\text{(Even)}}{\int_{-\pi}^\pi \frac{2 y \sin y}{1+\cos ^2 y} d y})
=0+2.2∫0πy(1+cos2ysiny)dyI=4∫0π1+cos2yysinydyI=4∫0π1+cos2y(π−y)sinydy2I=4∫0π1+cos2yπsinydyI=2π∫0π1+cos2ysinydy=2π(−tan−1(cosy))0π=−2π[(−4π)−(4π)]=−2π[−42π]=π2$$