<p>That’s just stupid. Even if you and the girl next to you got the same wrong answers by coincidence, the steps you both took to obtain your answers must have been different, right? See if anyone else in your class also got the same problems wrong. Go to the dean of the math department and show him the same problem you worked out on the board for your professor–it’s absurd that just because your professor couldn’t follow your steps on the board that he thought you were cheating. If your professor couldn’t follow what you did, see if the dean could.</p>