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. [tex] 62 [/tex]
D. [tex] 64 [/tex]

Answer :

Let's find [tex]\( f(3) \)[/tex] for the function [tex]\( f(x) = -5x^2 - x + 20 \)[/tex].

To do this, we simply need to substitute [tex]\( x = 3 \)[/tex] into the function and calculate the result:

1. Start with the function:
[tex]\[
f(x) = -5x^2 - x + 20
\][/tex]

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

3. Calculate [tex]\( 3^2 \)[/tex]:
[tex]\[
3^2 = 9
\][/tex]

4. Multiply by [tex]\(-5\)[/tex]:
[tex]\[
-5 \times 9 = -45
\][/tex]

5. Subtract [tex]\( 3 \)[/tex]:
[tex]\[
-45 - 3 = -48
\][/tex]

6. Add [tex]\( 20 \)[/tex]:
[tex]\[
-48 + 20 = -28
\][/tex]

Therefore, [tex]\( f(3) = -28 \)[/tex]. The correct answer is [tex]\(-28\)[/tex].