∫xarctanxdx
=∫arctanxd(0.5*x^2)
=0.5*x^2 *arctanx-∫0.5*x^2d(arctanx)
=0.5*x^2 *arctanx-∫0.5*x^2/(1+x^2)dx
=0.5*x^2 *arctanx-0.5*∫(1-(1/(1+x^2))dx
=0.5*x^2 *arctanx-0.5*∫dx+0.5*∫(1/(1+x^2))dx
=0.5*x^2 *arctanx-0.5x+0.5*arctanx+C
追问能写成2分之几的形式吗,谢谢
追答可以的,因为
0.5=1/2