∫xsin(x^2+1)dx
因为d(x^2)=2xdx
所以上面式子
=(1/2)*∫sin(x^2+1)d(x^2)
=(1/2)*∫sin(x^2+1)d(x^2+1)
=(1/2)*(-cos(x^2+1))
=-[cos(x^2+1)]/2
∫xsin(x^2+1)dx
因为d(x^2)=2xdx
所以上面式子
=(1/2)*∫sin(x^2+1)d(x^2)
=(1/2)*∫sin(x^2+1)d(x^2+1)
=(1/2)*(-cos(x^2+1))
=-[cos(x^2+1)]/2