Question

Consider the function f x =x 2 − 4x. If x=3 is a value in the domain of the function, then what is the value of f x when x=3?

Answer 1

Answer: correct aswer is -3

Explanation:

Answer 2

f(x) = -3

Explanation:

`{ \tt{f(x) = {x}^(2) - 4x}}`

- When x = 3, it implies that f(x) = f(3)

`{ \tt{f(3) = {(3)}^(2) - 4(3) }} \\ { \tt{f(3) = 9 - 12}} \: \: \: \: \: \: \: \\ { \tt{f(3) = - 3}} \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \:`

- So, the range, f(x) = -3