# One sided limit

1. Sep 9, 2008

### JennyInTheSky

1. The problem statement, all variables and given/known data
lim$$_{x\rightarrow4^{-}}$$ $$\frac{\sqrt{x}-2}{x-4}$$

2. Relevant equations
Typical methods used in solving one-sided limit.

3. The attempt at a solution
I plug in something a little bit bigger than four, like 4.0000001 into x, and I get $$\frac{something a little less than zero}{something a little less than zero}$$ to equal 1. But the answer is 1/4. How is this so?

2. Sep 9, 2008

### altcmdesc

Multiply both the top and the bottom by $$\sqrt{x}+2$$. This is called "multiplying by the conjugate" and is pretty standard for dealing with limits involving square roots