Answer :
To find the value of the function [tex]\( f(x) = -5x^2 - x + 20 \)[/tex] at [tex]\( x = 3 \)[/tex], we substitute [tex]\( 3 \)[/tex] into the function:
1. Start with the function:
[tex]\( f(x) = -5x^2 - x + 20 \)[/tex].
2. Substitute [tex]\( 3 \)[/tex] for [tex]\( x \)[/tex]:
[tex]\( f(3) = -5(3)^2 - 3 + 20 \)[/tex].
3. Calculate [tex]\( 3^2 \)[/tex]:
[tex]\( 3^2 = 9 \)[/tex].
4. Multiply [tex]\(-5\)[/tex] by [tex]\( 9 \)[/tex]:
[tex]\(-5 \times 9 = -45\)[/tex].
5. Substitute [tex]\(-45\)[/tex] into the expression:
[tex]\( f(3) = -45 - 3 + 20 \)[/tex].
6. Subtract [tex]\(3\)[/tex] from [tex]\(-45\)[/tex]:
[tex]\(-45 - 3 = -48\)[/tex].
7. Add [tex]\(20\)[/tex] to [tex]\(-48\)[/tex]:
[tex]\(-48 + 20 = -28\)[/tex].
So, the value of [tex]\( f(3) \)[/tex] is [tex]\(-28\)[/tex].
1. Start with the function:
[tex]\( f(x) = -5x^2 - x + 20 \)[/tex].
2. Substitute [tex]\( 3 \)[/tex] for [tex]\( x \)[/tex]:
[tex]\( f(3) = -5(3)^2 - 3 + 20 \)[/tex].
3. Calculate [tex]\( 3^2 \)[/tex]:
[tex]\( 3^2 = 9 \)[/tex].
4. Multiply [tex]\(-5\)[/tex] by [tex]\( 9 \)[/tex]:
[tex]\(-5 \times 9 = -45\)[/tex].
5. Substitute [tex]\(-45\)[/tex] into the expression:
[tex]\( f(3) = -45 - 3 + 20 \)[/tex].
6. Subtract [tex]\(3\)[/tex] from [tex]\(-45\)[/tex]:
[tex]\(-45 - 3 = -48\)[/tex].
7. Add [tex]\(20\)[/tex] to [tex]\(-48\)[/tex]:
[tex]\(-48 + 20 = -28\)[/tex].
So, the value of [tex]\( f(3) \)[/tex] is [tex]\(-28\)[/tex].
