用凑微分法算这题,怎么做的啊,求写出步骤

2025-05-01 05:30:38
推荐回答(1个)
回答1:

设x=t^2 原式为∫arctant * 1/(t(1+t²)) d(t²)
=2∫arctant * 1/(1+t²)dt
=2∫arctant d(arctant)
=arctant ²