Question

For all values of x,f(x) = x^2 + 3x and g(x) = x - 4Show that fg(x) = x^2 - 5x + 4​

Answer 1

Answer:

f(g(x)) =  x² - 5x +4

Step-by-step explanation:

Explanation

Given that the functions

         f(x) = x² + 3 x   and g(x) = x-4

     f(g(x)) = f(x -4)   (∵ g(x) = x-4)

              = (x-4)² + 3(x-4)

              = x² - 2(4)x + 4² + 3x -12

             = x² - 8 x + 16 + 3x -12

             = x² - 5x +4

∴ f(g(x)) =  x² - 5x +4