Question

If f(x) = −-4x^{2} + 15, then f(−3) =

Answer 1

`\Huge \boxed{-21}`

Explanation:

`f(x) = -4x^(2) + 15`

f(-3), the input is -3 for the function f(x).

The value of x = -3

`f(-3) = -4(-3)^(2) + 15`

Evaluate the expression.

`f(-3) = -4(9)+ 15`

`f(-3) = -36+ 15`

`f(-3)=-21`

The value of f(-3) is -21.

Answer 2

f(-3) = -21

Explanation:

To find f(-3), we just need to plug x = -3 into f(x) so:

f(-3) = -4 * (-3)² + 15

= -4 * 9 + 15 = -36 + 15 = -21