I need some help with understanding this:
[url=http://www.math.ucdavis.edu/~kouba/CalcOneDIRECTORY/preclimsoldirectory/PrecLimSol.html#SOLUTION%204]http://www.math.ucdavis.edu/~kouba/CalcOneDIRECTORY/preclimsoldirectory/PrecLimSol.html#SOLUTION%204[/url]
Refer to the part where we arbitrarily assume d<=1. I don't understand this part. I know d is an arbitrary number, but will it affect the results if I let the range of d be anything else other than 1? What if I choose d to be 100?

Oh I get it, after looking at the question-answers again. I think the point is to find delta in terms of epsilon, then prove the limit is true, not prove the delta-epsilon expression again. Am I right to say that?

Yeah pretty much. The way I see it is you find delta in terms of epsilon to prove if limit is true.

Nice, thank you everybody!