Answer :
To find [tex]\( f(3) \)[/tex] for the function [tex]\( f(x) = -5x^2 - x + 20 \)[/tex], follow these steps:
1. Substitute 3 into the function:
Replace [tex]\( x \)[/tex] with 3 in the expression for [tex]\( f(x) \)[/tex]. So you have:
[tex]\[
f(3) = -5(3)^2 - 3 + 20
\][/tex]
2. Calculate [tex]\((3)^2\)[/tex]:
[tex]\[
(3)^2 = 9
\][/tex]
3. Multiply by [tex]\(-5\)[/tex]:
[tex]\[
-5 \times 9 = -45
\][/tex]
4. Substitute back into the function:
You now have:
[tex]\[
f(3) = -45 - 3 + 20
\][/tex]
5. Perform addition and subtraction:
[tex]\[
f(3) = -45 - 3 = -48
\][/tex]
[tex]\[
-48 + 20 = -28
\][/tex]
Therefore, the value of [tex]\( f(3) \)[/tex] is [tex]\(-28\)[/tex].
1. Substitute 3 into the function:
Replace [tex]\( x \)[/tex] with 3 in the expression for [tex]\( f(x) \)[/tex]. So you have:
[tex]\[
f(3) = -5(3)^2 - 3 + 20
\][/tex]
2. Calculate [tex]\((3)^2\)[/tex]:
[tex]\[
(3)^2 = 9
\][/tex]
3. Multiply by [tex]\(-5\)[/tex]:
[tex]\[
-5 \times 9 = -45
\][/tex]
4. Substitute back into the function:
You now have:
[tex]\[
f(3) = -45 - 3 + 20
\][/tex]
5. Perform addition and subtraction:
[tex]\[
f(3) = -45 - 3 = -48
\][/tex]
[tex]\[
-48 + 20 = -28
\][/tex]
Therefore, the value of [tex]\( f(3) \)[/tex] is [tex]\(-28\)[/tex].
