Question

Find f(−1) given f(x)=−3x3+2x2+24
A. -23
B. 28
C. 29
D. 23

Answer 1

C. 29

Explanation:

`f(x) = -3x^3 + 2x^2 +24`

• To calculate
`f(-1)` , we have to replace x with -1 in the definition of
`f(x)` , and calculate the value:

`f(-1) = -3(-1)^3 + 2(-1)^2 + 24`

⇒
`-3(-1) +2(1) + 24`

⇒
`3 + 2 + 24`

⇒
`29`

Answer 2

`\huge\boxed{\textsf{C.}\ 29}`

We have this equation:

`f(x)=-3x^3+2x^2+24`

Substitute
`x=-1`:

`f(-1)=-3(-1)^3+2(-1)^2+24`

Simplify to find the final answer:

`\begin{aligned}f(-1)&=-3(-1)+2(1)+24\\&=3+2+24\\&=5+24\\&=\boxed{29}\end{aligned}`