Watson's Lemma - Asymptotic Evaluation Integrals

[MidnightR]

[PLAIN]http://img42.imageshack.us/img42/8669/20183046.jpg

Need to show it is approx. equal to (1/3)!/x^(1/3)

Any suggestion of further substitution? I need to change the limits.

 

[MidnightR]

Any ideas? Been thinking about this for a while now, still stumped :-\ Shame as I can do all the other questions.

 

[hunt_mat]

integration by parts is usually the way to go with these. There are two different ways to go about ths depending in x is small or large.