先化简,令t=arcsin(x) ,则 x=sin(t) arccos(x)=π/2 -t 原式=∫t(π/2 -t)dsin(t)=t(π/2 -t)sin(t) -∫ sint d(t(π/2 -t))=t(π/2 -t)sin(t) -∫ (π/2-2t)sint dt=t(π/2 -t)sin(t) +∫ (π/2-2t) dcos(t)=t(π/2...你太牛了！！！