College Algebra

Question

Let f(x) = x - 3 and g(x) = x^2 + 4x. Find (fºg)(x) and (gºf)(x).

Answer 1

Hello, thank you for taking the time to post your question!

(f o g)(x) = f(g(x)) = f(x^2 + 4x) = x^2 + 4x – 3

(g o f)(x) = g(f(x)) = g(x – 3) = (x – 3)^2 + 4(x – 3) = x^2 – 6x + 9 + 4x – 12 = x^2 – 2x – 3

I hope that helps you get moving in a better direction on this type of question! Feel free to reach out if you have any additional questions beyond that :)

Answer 2

(f°g)(x) = x² + 4x - 3

(g°f)(x) = (x-3)² + 4(x-3) = x²-6x+9+4x-12=x²-2x-3