How to find the pre-image of the set if this function maps from real numbers to real numbers. What command would I use, to see the pre-image if the function would map from integers to integers.
It is easy to compute with mathematica, but the command to find the pre-image I cannot find.
What I tried, and there are no methods available to solve it:
Solve[y == 3^x - 17 Floor[3^x/17], x]