原式=-∫1/2*√(1-x²)arcsinxd(1-x²)=-∫1/2*2/3arcsinxd(1-x²)^(3/2)=-1/3*(1-x²)^(3/2)*arcsinx+1/3∫(1-x²)^(3/2)darcsinx=-1/3*(1-x²)^(3/2)*arcsinx+1/3∫(1-x²)^(3/2)*1/√(1-x²)dx=-1/3*(1-x²)^(3/2)*arcsinx+1/3∫(1-x²)dx=-1/3*(1-x²)*√(1-x²)*arcsinx+x/3-x³/9+C