I don't have much experience in this, and hopefully someone can recommend the right type of book that I need to look thru in order to solve future problems like this. I have to have a formula for the nth derivative. I have like in the numerator, but Idk how to express it properly. 5 5 x 10 5 x 10 x 15 ... So, my formula would be something like: (5n)! In my book, it says that n! = 1 x 2 x 3 ... (n-1) x n?