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 find [tex]\( f(3) \)[/tex] for the function [tex]\( f(x) = -5x^2 - x + 20 \)[/tex], we substitute [tex]\( x = 3 \)[/tex] into the function and calculate the result step-by-step:

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. Substitute back and continue with the calculation:
[tex]\[
f(3) = -45 - 3 + 20
\][/tex]

6. Compute [tex]\(-45 - 3\)[/tex]:
[tex]\[
-45 - 3 = -48
\][/tex]

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

So, the value of [tex]\( f(3) \)[/tex] is [tex]\(-28\)[/tex].