积分∫√(x^2-a^2)/xdx

问题描述:

积分∫√(x^2-a^2)/xdx
分母是x 分子是√x^2-a^2

设x=asect
原式=a∫tant/sect d(sect)
=a∫sint d(sect)
=asintsect-a∫sect d(sint)
=asintsect-a∫dt
=asintsect-a
再代回x