College

Given the function [tex]f(x) = -5x^8 - x + 20[/tex], find [tex]f(3)[/tex].

A. -28
B. -13
C. 62
D. 64

Answer :

To find [tex]\( f(3) \)[/tex] for the function [tex]\( f(x) = -5x^8 - x + 20 \)[/tex], we need to substitute [tex]\( x = 3 \)[/tex] into the function and simplify.

1. Start with the function:
[tex]\[
f(x) = -5x^8 - x + 20
\][/tex]

2. Substitute [tex]\( x = 3 \)[/tex] into the function:
[tex]\[
f(3) = -5(3)^8 - 3 + 20
\][/tex]

3. Calculate [tex]\( 3^8 \)[/tex]:
[tex]\[
3^8 = 6561
\][/tex]

4. Substitute [tex]\( 6561 \)[/tex] back into the expression:
[tex]\[
f(3) = -5(6561) - 3 + 20
\][/tex]

5. Calculate [tex]\(-5 \times 6561\)[/tex]:
[tex]\[
-5 \times 6561 = -32805
\][/tex]

6. Substitute [tex]\( -32805 \)[/tex] back into the equation and simplify:
[tex]\[
f(3) = -32805 - 3 + 20
\][/tex]

7. Perform the arithmetic operations:
[tex]\[
-32805 - 3 = -32808
\][/tex]

[tex]\[
-32808 + 20 = -32788
\][/tex]

So, the value of [tex]\( f(3) \)[/tex] is [tex]\(-32788\)[/tex].