Question

If f(x) = 1/2x^2 -(1/4x + 3), what is the value of f(8)?

Answer 1

To find the value of
`\sf f(8) \\` for the function
`\sf f(x) = (1)/(2)x^2 - \left((1)/(4)x + 3\right) \\`, we substitute
`\sf x = 8 \\` into the function.

`\sf f(8) = (1)/(2)(8)^2 - \left((1)/(4)(8) + 3\right) \\`

Simplifying inside the parentheses:

`\sf f(8) = (1)/(2)(64) - \left((1)/(4)(8) + 3\right) \\`

`\sf f(8) = 32 - \left(2 + 3\right) \\`

`\sf f(8) = 32 - 5 \\`

Finally, subtracting:

`\sf f(8) = 27 \\`

Therefore, the value of
`\sf f(8) \\` is 27.

Answer 2

f(8) = 27

Explanation:

to evaluate f(8) substitute x = 8 into f(x)

f(8) =
`(1)/(2)` × 8² - (
`(1)/(4)` (8) + 3)

=
`(1)/(2)` × 64 - (2+ 3)

= 32 - 5

= 27