Question

F(x) = x2+ x–1 and g(x) = x+ 3, what is f o g(x)

Answer 1

Explanation:

`f(x) = x^2 + x - 1\\g(x) = x +3\\\\\\(f\:o\:g)(x) = f(g(x))`

we input the function g(x) into every x in f(x)

`f(g(x)) = (x+3)^2 + (x + 3) - 1\\f(g(x)) = x^2 + 6x + 9 + x + 3 - 1\\f(g(x)) = x^2 + 7x + 11`