求不定积分∫1/(x²-x-2)dx
问题描述：
求不定积分∫1/(x²-x-2)dx
答
∫1/(x²-x-2)dx
=∫1/[(x-2)(x+1)]dx
=1/3∫[1/(x-2)-1/(x+1)]dx
=1/3ln(x-2)-1/3ln(x+1)+C