It's very hard to win Queen vs Rook game, unless your opponent doesn't know what he's doing.
I believe it would only be cheating if you actually got any hint on what move to do next. But if somebody simply said - it is possible to win Q vs. R, then it's not cheating - just a fact.
I played a game a few days ago where the following pieces were left on the board. I was white and sadly, I haven't studied the game enough to know if this was a game I could still win or not excluding a huge blunder on blacks part. I googled 'queen king rook king' and got my answer. Yes you can win if you are the queen, but since I had used google I decided to accept blacks offer for a draw. (Partly thanks to the movie Searching for Bobbie Fischer, that Oginshcille forced me to watch about offering a way out.) I honestly did not look at how to win the game but whether it was possible to win. Does it still mean I would have been cheating if I had continued the game?
PS... Thanks for all the comments and this is where white needs to put black to win. Notice that wherever black goes on it's next move, white will move the queen to mate.