Question

Which function below is the inverse of f(x) = x2 − 25?

Answer 1

(x-5)(x+5) is the answer

Answer 2

`f(x) = x^(2) - 25` can be written as
`y = x^(2) - 25`

when finding inverse the first step is to interchange x and y in the equation

∴
`(x) = (y)^(2) - 25`

then you simply solve for y


`x + 25 = y^(2)`


`y = √( (x + 25))`

Thus
`f^(-1) (x) = √((x + 25))`