If f(x) = 2x - 5 and g(x) = x^2 - 3, what is (g o f)(x)?

1 Answer
Oct 17, 2015

In order to solve (g o f)(x) for #f(x) = 2x - 5# and #g(x) = x^2 - 3#, the f(x) function must be substituted into the g(x) function.

The simplification of the function is
(g o f)(x) = #4x^2 -20x + 22#

Explanation:

In order to solve (g o f)(x) for #f(x) = 2x - 5# and #g(x) = x^2 - 3#, the f(x) function must be substituted into the g(x) function.

(g o f)(x) = #(2x - 5)^2 - 3#

(g o f)(x) = #(2x - 5)(2x - 5) - 3#

by FOIL (First Outer Inner Last)
(2x - 5)(2x - 5) = (2x)(2x) - 10x - 10x + 25
#4x^2 -20x + 25#

(g o f)(x) = #4x^2 -20x + 25 - 3#

(g o f)(x) = #4x^2 -20x + 22#