Find the limit of x^2(√(x^4+5)-x^2) as x->∞

1. Nov 15, 2011

NWeid1

Find the limit of x^2(√(x^4+5)-x^2) as x->∞. I think it might be a L'Hospitals rule, but I'm not sure. We haven't done many problems like this yet, thanks!

2. Nov 15, 2011

SteamKing

Staff Emeritus
L'Hospital's Rule is valid only for certain indeterminate forms, like infinity/infinity or 0/0.
You should be able to determine this limit by inspection.

3. Nov 15, 2011

Staff: Mentor

Right. L'Hopital's Rule is not applicable here.
I don't know about that. This limit is another of the indeterminate forms - [∞ * 0].

I would multiply the expression in the limit by 1, in the form of $\sqrt{x^4 + 5} + x^2$ over itself.