I follow the L'Hopital's Rule method of solving this problem, but where did you get the "
This is a given identity thinger I should be familiar with? I haven't come across it, please let me know the deal.
This is just one of many
ways of representing
. It would be unreasonable to learn them all
by heart, but a familiarisation with their general forms may alert you to the possibility of
hiding in a particular problem. Learning a few of the simpler ones, like this, may prove useful (and save a lot of time).
In fact, by using the more general version
of this representation of
, the second solution can be simplified further:Q.
Thinking about where this question originally came from, Temple University's 'Calculus on the Web' site, and the simplicity of the other 22 questions leading up to this one, I would imagine that the question may be testing for knowledge of this very representation of