For the function f defined by f(x) = 3x^2 + 3x +4, find the following values.

Question

(a) f(-9) = 220

(b) f(-x) = 3x^2 -3x+4

(c) -f(x) =

(Simplify your answer.)

Answer 1

It seems like you already have the answers for parts A and B, so I will just work out part C.

f(x) = 3x^2 + 3x + 4

We can find -f(x) by multiplying both sides of the above equation by -1

(-1)f(x) = (-1)(3x^2 + 3x + 4)

Then simplify,

-f(x) = -3x^2 - 3x - 4 [Distribute the -1 through the parentheses]