# Homework Help: 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.