Video in reference: https://youtu.be/dUwN6GI-0EQ after 4:05
In a Cambridge (model) interview, someone was asked to sketch a graph of sin(x)/x. The intention was clearly that they were not to have seen this function before. When watching, I immediately recognised this as sinc(x) (a function sometimes used in electrical engineering). They were then told not to evaluate this function at 0 because it's difficult, however I knew how this could be done. If I was in this position, would it be acceptable to pretend like I could derive everything I knew about this function already to impress the interviewer, or important to say that I have already seen the function before.