[질문] 싸인네제곱엑스적분 어뜨케함

sin^4 x=(1-cos^2 x) * sin^2 x=sin^2 x - cos^2 x *sin^2 x=(1-cos2x)/2 - (sin^2 2x)/4 =(1-cos2x)/2-(1-cos4x)/4. 이걸적분 (1/4)x-(1/4)sin2x+(1/8)sin4x