# Homework Help: Problem Calculating a limit with a square root, i'm stuck

1. Jan 21, 2010

### Jordash

Problem Calculating a limit with a square root, i'm stuck :(

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

The limit is equation 9-t / 3-sqrt(t) as t approaches 9

I'm stuck on the how to simplify this?

Thanks for any help.

2. Relevant equations

3. The attempt at a solution

2. Jan 21, 2010

### rock.freak667

Re: Problem Calculating a limit with a square root, i'm stuck :(

Try multiplying by (3+√t)/(3+√t)

3. Jan 21, 2010

### Jordash

Re: Problem Calculating a limit with a square root, i'm stuck :(

I discovered that that is the conjugate and I came out with this:

27-6sqrt(t)-tsqrt(t)
----------------
9-t

So in other words, that limit does not exist. Is that right?

4. Jan 21, 2010

### Staff: Mentor

Re: Problem Calculating a limit with a square root, i'm stuck :(

The limit does exist. Instead of multiplying by the conjugate over itself, just factor the numerator, treating it as the difference of two squares.