College

Given the function [tex]f(x) = -5x^2 - x + 20[/tex], find [tex]f(3)[/tex].

A. -28
B. -13
C. 62
D. 64

Answer :

To evaluate the function
[tex]$$
f(x) = -5x^2 - x + 20
$$[/tex]
at [tex]$x = 3$[/tex], follow these steps:

1. Substitute [tex]$x = 3$[/tex] into the function:
[tex]$$
f(3) = -5(3)^2 - (3) + 20
$$[/tex]

2. Compute the square of [tex]$3$[/tex]:
[tex]$$
3^2 = 9
$$[/tex]

3. Multiply by [tex]$-5$[/tex]:
[tex]$$
-5 \times 9 = -45
$$[/tex]

4. Now, substitute these values back into the expression:
[tex]$$
f(3) = -45 - 3 + 20
$$[/tex]

5. Finally, combine the terms:
[tex]$$
-45 - 3 = -48 \quad \text{and} \quad -48 + 20 = -28
$$[/tex]

Thus, the value of [tex]$f(3)$[/tex] is
[tex]$$
\boxed{-28}
$$[/tex]