Could someone please show me how to prove that this limit is 0 by the squeeze/sandwich theorem in a way as simple as possible. Im not very good with all the technical math descriptions. The sequence is a=(-4)^n/n!
Since alternates between negative and positive, an obvious "sandwiching" will be between and . One way to prove that goes to 0 is to show that converges since a necessary condition that a series converge is that the sequence of term go to 0. You can do that by using the "ratio test" or even by noting that the series converges to .