College

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

A. [tex]\(-28\)[/tex]
B. [tex]\(-13\)[/tex]
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]:

[tex]$$ f(3) = -5(3)^2 - 3 + 20. $$[/tex]

2. Calculate the square:

[tex]$$ 3^2 = 9. $$[/tex]

3. Multiply by [tex]$-5$[/tex]:

[tex]$$ -5(9) = -45. $$[/tex]

4. Combine the other terms:

The function now becomes

[tex]$$ f(3) = -45 - 3 + 20. $$[/tex]

5. Add the terms sequentially:

First, add [tex]$-45$[/tex] and [tex]$-3$[/tex]:

[tex]$$ -45 - 3 = -48. $$[/tex]

Then add [tex]$20$[/tex]:

[tex]$$ -48 + 20 = -28. $$[/tex]

Thus, the value of [tex]$f(3)$[/tex] is

[tex]$$
\boxed{-28}.
$$[/tex]