Question

If f(x) = -x^2 – 1, and
g(x) = x + 5, then
g(f (x)) = [? ]x^2+[ ]x + [ ]

Answer 1

g(f(x)) = - x² + 4

Explanation:

To evaluate g(f(x)), substitute x = f(x) into g(x), that is

g(f(x))

= g(- x² - 1)

= - x² - 1 + 5

= - x² + 4