∫ex(ex−1) (ex+2) dx=

∫ex(ex−1)(ex+2) dx                ex=t⇒exdx=dt ∫1(t−1)(t+2)dt=13∫1(t−1)-1(t+2)dt =13log|t−1t+2|+c                                 =13log|ex−1ex+2|+c