鲁芽网认证
∫arccotxdx=xacrccotx-∫xd(arccotx)=xacrcotx-∫x(-1/(x*x+1))dx=xacrcotx + (1/2)∫1/(x*x+1)d(x*x)=xacrcotx + (1/2)∫1/(x*x+1)d(x*x+1)=xacrcotx + (1/2)ln(x*x+1)+C