计算不定积分∫arctan√xdx

题目

计算不定积分∫arctan√xdx

答案

√x=tx=t²dx=2tdt∫arctan√xdx=∫2tarctantdt=∫arctantdt²=t²arctant-∫t²/(1+t²)dt=t²arctant-∫(1+t²-1)/(1+t²)dt=t²arctant-∫1-1/(1+t²)dt=t²arctant...