A factorial is just the product of the first n positive integers. For instance, 4! is the product of 1*2*3*4 = 24.
Usually the terms are multiplied in reverse order.....so 4! is usually writen as 4*3*2*1. (I'm not sure that there is any particular justification for doing this, but maybe someone else knows why....)
Let me throw one more thing in....by definition, 0! = 1
Does that help, DS???
A factorial is just the product of the first n positive integers. For instance, 4! is the product of 1*2*3*4 = 24.
Usually the terms are multiplied in reverse order.....so 4! is usually writen as 4*3*2*1. (I'm not sure that there is any particular justification for doing this, but maybe someone else knows why....)
Let me throw one more thing in....by definition, 0! = 1
Does that help, DS???