Question 1028661
Let y = f(x). We want to solve y = f(y).


Solving y = f(y) gives y = y^2 - 2y or y = 0, 3. Then we want to solve f(x) = 0, f(x) = 3.


If f(x) = 0, then x^2 - 2x = 0 --> x = 0 or 2.
If f(x) = 3, then x^2 - 2x = 3 --> x = 3 or -1.


Solutions: 0, -1, 2, 3