Academic dishonesty -- math graduate school admissions
This is certainly not going to help your application for graduate school, and it can be fatal if it doesn't look like you've learned from it. I suspect the default position of most people is going to be against you, unfortunately.


If you still have time (i.e. years till you graduate), make sure to show that you can put the incident behind you. Don't cheat in other classes, but get good grades in them anyway.
If you don't have time, that's bad. You'll need to write a good explanation in your application.
You will be asked about this. There's a box in many graduate applications asking if you've ever been involved in academic dishonesty situations. Don't omit this even if you've put the incident behind you, because if you do, you are not reporting full facts and if discovered any offer of admission can be rescinded even if you've already matriculated (see the statement you have to sign at the end of the application).