Question

Please, I need help: Define the function $f(x) = 2x - 5$. For what value of $x$ is $f(x)$ equal to $f^{-1}(x)$?

Answer 1

5

Explanation:

A function is equal to its inverse on the line y = x. So, we can find the required value of x by substituting for y:

y = 2x -5

x = 2x -5 . . . . substitute y = x

5 = x . . . . . add 5-x to both sides