Question

Let f(x) = 2x3 – 4x.
Find f(-2).

Answer 1

We have
`f(x)=2x^3-4x`, to find
`f(-2)` put -2 instead of x,
`f(-2)=2(-2)^3-4(-2)=-16+8=\boxed{-8}`.

Hope this helps.

Answer 2

Explanation:

f(x) = 2x^3 - 4x.....find f(-2).....so sub in -2 for x

f(-2) = 2(-2^3) - 4(-2)

f(-2) = 2(-8) + 8

f(-2) = -16 + 8

f(-2) = -8 <==