simple forms of limits

[anmolnanda]

LIMx\rightarrowinfinite (bn+an)1/n
it is given that 0<a<b
in this case why do we take bn or an common to make the inside element 0...and how do u guys take to solve this kind of situation how do u think?

[micromass]

This can help: http://en.wikipedia.org/wiki/Generalized_mean
Look at 4.4