∫arctan√xdx要详解
1个回答

原式= x arctan√x - ∫x d (arctan√x)

令t=√x,则 ∫x d (arctan√x) = ∫ t^2 d (arctant) = ∫ t^2 / (1+ t^2) dt = ∫ (t^2+1-1) / (1+ t^2) dt

= ∫ 1 dt - ∫ 1 / (1+ t^2) dt

= t - arctan t + C

将t=√x带入 = √x - arctan√x +C

所以原式= x arctan√x - √x + arctan√x +C