Let f(x) = 4x - 7 and g(x) = 6 - 2x where f(x) : R → R, and g(x) : R → R. Find (f ◦ g)(x).

Question

Let f(x) = 4x - 7 and g(x) = 6 - 2x where f(x) : R → R, and g(x) : R → R. Find (f ◦ g)(x).

Answer 1

(fog)(x)

= f(g(x)

=f(6-2x) (Plugging in the expression of g(x))

=4(6-2x) - 7 (Plugging 6 - 2x in place of x in expression of f(x))

=24 - 8x -7

=17-8x

This is known as 'Composition of Functions'