Question

Let f(x) = 2x^2 –1 and g(x) = –5x. Write a function rule representing (g ◦ f)(x).

–10x^3 + 5x

–10x^3 – 5x

50x^2 – 1

–10x^2 + 5

Answer 1

(g ◦ f)(x) = g(f(x)) = g(2x^2 − 1) = −5(2x^2 − 1) = −10x^2 + 5.