関連ワード:  integrate sin 2 theta d theta from 0 to pi    integrate sin^4 theta d'theta from 0 to pi/2    integrate (cos theta)/(cos theta + sin theta) d'theta from 0 to pi / 2 =    integrate (sin theta + cos theta) d'theta from 0 to pi / 2  
結果 : integrate sin 2 theta d theta from 0 to pi