Интеграл dx/(x-1)(x+2)

=∫ 1/3(1/(x-1)-1/(x+2))dx=(1/3)( ∫1/(x-1)dx - ∫1/(x+2)dx)=(1/3)[ln(x-1)-ln(x+2)]+c
=(1/3) ln((x-1)/(x+2)) +c