Question

I do not know how to do this need help

Answer 1

Remark

First of all you have to declare the meaning of g(f(x)) After you have done that, you have to make the correct substitution.

Givens

f(x) = 4x^2 + x + 1

g(x) = x^2 - 2

Discussion

What the given condition g(f(x)) means is that you begin with g(x). Write down g(x) = x^2 -  2

Wherever you see an x on either the left or right side of the equation, you put fix)

Then wherever you see f(x) on the right you put in what f(x) is equal to.

Solution

g(x) = x^2 - 2

g(f(x)) = (f(x))^2 - 2

g(f(x)) = [4x^2 + x + 1]^2 - 2

f(x)^2 =

4x^2 + x + 1

4x^2 + x + 1

16x^4 + 4x^3 + 4x^2

            4x^3  + x^2 +   x

                        4x^2 + x  + 1

16x^4 + 8x^3 + 9x^2 + 2x + 1

Answer

g(f(x)) = 16x^4 + 8x^3 + 9x^2 + 2x + 1 - 2

g(f(x)) = 16x^4 + 8x^3 + 9x^2 + 2x - 1