Let be a differentiable function such that for all real

MATHEMATICS · Single correct · A Level · Mathematics · Differentiation · Differentiation

Problem

Let

h

be a differentiable function such that

h'(x)=(x-2)(x+1)

for all real

x

. On which of the following intervals is

h

decreasing? (a)

(-\infty,-1)

(b)

(2,\infty)

(c)

(-1,2)

(d)

(-\infty,-1)\cup(2,\infty)