f f(x)=x2+4x+8

Question

, what is f(−1)
?(1 point)
Responses

3
3

11
11

5
5

13

Answer 1

To find \( f(-1) \) for the function \( f(x) = x^2 + 4x + 8 \), we substitute \(-1\) for \(x\):

\[ f(-1) = (-1)^2 + 4(-1) + 8 \]

Calculating each term:

\[ (-1)^2 = 1 \]

\[ 4(-1) = -4 \]

Now substituting these into the equation:

\[ f(-1) = 1 - 4 + 8 \]

Now, simplifying:

\[ f(-1) = 1 - 4 + 8 = -3 + 8 = 5 \]

Thus, \( f(-1) = 5 \).

The answer is 5.