In the deleted scene where Professor Snape asks Harry questions in class, and Harry doesn't know (Hermione has her hand up).
Professor Snape: "Clearly, fame isn't everything - is it, Mr Potter?" Harry: "Clearly, Hermione knows. It's a pity not to ask her"
This draws giggles from the class, and Snape deducts points off Griffindoor for Harry's "cheek".
So yeah, what was cheeky about Harry's comment? He is saying that Hermione knows the answers so why not ask her - does this alone sound cheeky as he is sorta telling the Professor what to do?
I believe that marinalva1996 is correct, I bet he thought Harry was being a smarts because of his comment, and it is plain to see that Hermione knows the answer because she raised her hand after each question, And is shown later then that Snape clearly hates her, even for all the time she would talk out of turn even when she was in a class he was subbing for, since I believe this is the only scene that are in class with Snape without him being a fill in teacher for the regular teacher, which mainly seen was Defense against the dark arts. But you would think that he should have thought there is no way that Harry would know any answers since it was only very recently he even learned he was a Wizard. Where I bet somehow Hermione must have known that she was a witch, and had a few years to read up on magical stuff like Howarts: a history once she learned how to read.
Well of course! It was Snape! He takes it out on Harry because Lily Potter did not choose him over James. He would want to make sure to degrade Harry and what better way then to give him questions he could not answer.
Actually, I have had that happen to me in class many times. Teachers would typically do that if I was talking to someone else or I was not paying attention.
i just merely thought he did it after Harry's talking back with that attitude. and remember, Harry wasn't paying attention while everyone else was. Snape asked Harry, not Hermione. it was just one of those instances where the teacher asks a student questions to make sure they're paying attention in class
and i don't think Snape hated Hermione. remember he called her a know-it-all which does annoy people. i mean, come on, give the other kids a chance to answer. she didn't need to answer every single thing
He is being cheeky. Harry didn't say it just to let Snape know Hermione knew the answers, he said it because Snape was intentionally picking on him and insulting him, deriding him by calling Harry the new resident celebrity and when he couldn't answer questions on his first day of class, telling Harry that fame isn't everything. Harry used his words back at him and intentionally fought back.