Question

For what values of x is f(x) = square root of x-4 equal to 4?

Answer 1

x = 20

Explanation:

given f(x) =
`√(x-4)`, we have to solve

`√(x-4)` = 4

Square both sides

(
`√(x-4)`)² = 4²

x - 4 = 16 ( add 4 to both sides )

x = 20

As a check

`√(20-4)` =
`√(16)` = 4 ← correct