Question

Given the function f(x)=-5x^2-x+20, find f(3)

Answer 1

To find f(a) for any function, plug a into that function. Like so:

↔ f(x) = -5x² - x + 20

↔ f(3) = -5(3)^2 - 3 + 20

↔ f(3) = -5 * 9 - 3 + 20

↔ f(3) = -45 - 3 + 20

↔ f(3) = -48 + 20

↔ f(3) = -28

Answer 2

f(3) = -28

Explanation:

Given the function:

`\sf f(x) = -5x^2 - x + 20`

To find f(3), we simply substitute 3 for x in the function. So, we have:

`\sf f(3) = -5 *( 3)^2- (3) + 20`

`\sf f(3) = -5 * 9 - 3 + 20`

`\sf f(3) = -45 - 3 + 20`

`\sf f(3) = -48 +20`

`\sf f(3) = -28`

Therefore, f(3) = -28.