If f(x)=∫ex2(x−2)(x−3)(x−4)dx
then f increases on
(−∞,2)
(2, ∞)
(2, 3)
(3, ∞)
f′(x)=ex2(x−2)(x−3)(x−4)
As ex2>0 for all x∈R,f′(x)>0
if (x−2) (x−3) (x−4)>0 i.e., if 2<x<3 or x>4
Thus f(x) increases on the interval (2, 3)