1.3.2a Composite Function (Comparison Method) Example 1

Example 1
Given

f : x \mapsto h x + k, g : x \mapsto {(x + 1)}^{2} + 4

and

f g : x \mapsto 2 {(x + 1)}^{2} + 5.

Find
(a) the value of g²(2),
(b) the value of h and of k.