Answer :
To find [tex]\( f(3) \)[/tex] for the function [tex]\( f(x) = -5x^2 - x + 20 \)[/tex], you simply need to evaluate the function at [tex]\( x = 3 \)[/tex]. Here is how you can do it step-by-step:
1. Plug in the value of [tex]\( x = 3 \)[/tex] into the function:
[tex]\[
f(3) = -5(3)^2 - (3) + 20
\][/tex]
2. Calculate [tex]\( (3)^2 \)[/tex]:
[tex]\[
3^2 = 9
\][/tex]
3. Multiply -5 by 9:
[tex]\[
-5 \times 9 = -45
\][/tex]
4. Substitute back into the function:
[tex]\[
f(3) = -45 - 3 + 20
\][/tex]
5. Simplify the expression step-by-step:
- First, add the [tex]\(-45\)[/tex] and [tex]\(-3\)[/tex]:
[tex]\[
-45 - 3 = -48
\][/tex]
- Then, add [tex]\(20\)[/tex]:
[tex]\[
-48 + 20 = -28
\][/tex]
Therefore, the value of [tex]\( f(3) \)[/tex] is [tex]\(-28\)[/tex].
1. Plug in the value of [tex]\( x = 3 \)[/tex] into the function:
[tex]\[
f(3) = -5(3)^2 - (3) + 20
\][/tex]
2. Calculate [tex]\( (3)^2 \)[/tex]:
[tex]\[
3^2 = 9
\][/tex]
3. Multiply -5 by 9:
[tex]\[
-5 \times 9 = -45
\][/tex]
4. Substitute back into the function:
[tex]\[
f(3) = -45 - 3 + 20
\][/tex]
5. Simplify the expression step-by-step:
- First, add the [tex]\(-45\)[/tex] and [tex]\(-3\)[/tex]:
[tex]\[
-45 - 3 = -48
\][/tex]
- Then, add [tex]\(20\)[/tex]:
[tex]\[
-48 + 20 = -28
\][/tex]
Therefore, the value of [tex]\( f(3) \)[/tex] is [tex]\(-28\)[/tex].
