Finding the limit of a function as x approaches a.

[S-z]

For the function, f(x)=x^2 I need to find the limit as x approaches a. I am sure the limit is a^2, but how can I prove this, should I use the epsilon delta method? if so, am I to set delta to \sqrt{}epsilon?
thanks

 

[CompuChip]

Why don't you try it.

Let \epsilon > 0 and set \delta = \sqrt{\epsilon}.
If |x - a| < \delta then
|f(x) - a^2| = |x^2 - a^2| = \cdots \le \cdots \stackrel{?}{\le} \epsilon