你的问题可以化为
∫arctan(1/x) dx
于是可以用分部积分:
∫arctan(1/x) dx
=arctan(1/x)*x-∫x*1/(1+1/x^2) *(-1/x^2) dx
=arctan(1/x)*x+∫x*1/(1+x^2) dx
=arctan(1/x)*x+(1/2)∫1/(1+x^2) d(x^2+1)
=arctan(1/x)*x+(1/2)*ln(1+x^2)+c
你的问题可以化为
∫arctan(1/x) dx
于是可以用分部积分:
∫arctan(1/x) dx
=arctan(1/x)*x-∫x*1/(1+1/x^2) *(-1/x^2) dx
=arctan(1/x)*x+∫x*1/(1+x^2) dx
=arctan(1/x)*x+(1/2)∫1/(1+x^2) d(x^2+1)
=arctan(1/x)*x+(1/2)*ln(1+x^2)+c