Teacher

I am not sure where you are studying and what is the context of this question, it certainly sounds bizarre that your professor is asking you to cheat. Having said that, I am also aware that certain institutes allow open book/notes exams where students are allowed to refer to book and/or notes during the examination. I guess the objective being, with availability of all resources at your disposal, how well would you perform. Needless to say, in order to make effective use to books/notes, you should know what and where to refer and that in turn means you would have at least been through the books and notes once, if not more.
I am not sure, but I do hope that, this is the context and background with which your professor asked to cheat.