Question

Let f, g: R → R be defined by f(x) = 2x + 1 and g (x) = x² – 2, ∀ x ∈ R, respectively. Then, find g o f.

Answer 1

Given,

f(x) = 2x + 1 and g (x) = x² – 2, ∀ x ∈ R

Thus, g o f = g (f (x))

= g (2x + 1)

= (2x + 1)² – 2

= 4x² + 4x + 1 – 2

= 4x² + 4x – 1