# Finding the limit

1. Jan 8, 2009

### Fairy111

1. The problem statement, all variables and given/known data

Determine whether the following sequence has a limit. Find the limit if it exists.

2. Relevant equations

a(n)=cos[n/(2^n)]

3. The attempt at a solution

Im not sure how to go about finding the limit...do i use l'hopitals rule?

2. Jan 8, 2009

### NoMoreExams

Re: Limits

When talking about limits you usually specify limit as n approaches something, do you mean infinity?

3. Jan 8, 2009

### Fairy111

Re: Limits

It doesnt actually say in the question, so i am assuming it means as n tends to infinity.

4. Jan 8, 2009

### HallsofIvy

Staff Emeritus
Re: Limits

It should be obvious that n/2^n goes to 0 as n goes to infinity. Then use the fact that cos(x) is a continuous function.