1
$\begingroup$

Is the function $$f(x) = 7x + 11 \pmod{10}$$ invertible for all positive integers?

I don't know how to go about it, mainly because I have never dealt with functions such as this one.

  • 1
    Did you try to graph it? Do you know a condition that a function must have to be invertible?2012-11-28

2 Answers 2