1. Nov 15, 2011 #1

   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!

    

   NWeid1, Nov 15, 2011
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3. Nov 15, 2011 #2

   SteamKing

   

   Staff Emeritus

   Science Advisor

   Homework Helper

   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.

    

   SteamKing, Nov 15, 2011
4. Nov 15, 2011 #3

   Mark44

   

   Insights Author

   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 [itex]\sqrt{x^4 + 5} + x^2[/itex] over itself.

    

   Mark44, Nov 15, 2011

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