MATHEMATICS · Single correct · A Level · Mathematics · Differentiation · Differentiation
Problem
Let h(x) be differentiable for all x and let f(x)=(kx+ex)h(x), where k is a constant. If h(0)=5, h′(0)=−2, and f′(0)=18, then the value of k is:
(a) 5
(b) 4
(c) 3
(d) 2.2