Problem: Find the domain and limits at endpoints of its intervals for the function
Solution: Since exponential accepts any argument, there are two
conditions that determine the domain: The square root requires that
Therefore there are four limits to evaluate (when there is a point-sized hole in the domain, ti is usually better to do two one-sided limits there, although sometimes it turns out that a limit (both-sided) could have been done right away). We take it from the left, for tips on limit evaluation see e.g. Limits in Functions - Methods Survey.
Note that it was important to notice that
By the way, the results we learned suggest that the function goes like this.