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.