That's the correct answer, but find another solution without that rule.
Have you seen this problem before..or do you just have a knack for seeing embarrassingly obvious little tricks?
Why dont you submit a limit NonCommonAlg? That would be great, for I am sure it would be fascinating...but noting your other posts..it would preferably NOT include any of the following:
Limits involving sums
Limits involving sums esecially those excluding odd primes
Limits involving integrals
Limits involving integrals that require both countour integration and a parameterazation to solve
Limits involving infinite products
Limits involving anything to do with Wallis's Product
I am sure there are quite a few more