Hi,

Q1.

lim (x = infinity) { (X^2 +5x - 6)/(4x^2 +x -8) }

Q2.

lim (x = infinity) { x^2/(x+5) - x }

i know how to find limits of functions, but i dont know how to do it when x is infinity, please explain,

thanks

Moon

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- Dec 18th 2008, 08:44 PMMoon HopliteHelp! Limits of functions
Hi,

Q1.

lim (x = infinity) { (X^2 +5x - 6)/(4x^2 +x -8) }

Q2.

lim (x = infinity) { x^2/(x+5) - x }

i know how to find limits of functions, but i dont know how to do it when x is infinity, please explain,

thanks

Moon - Dec 18th 2008, 09:13 PMMentia
When you have a limit that looks like 0/0 or Infinity/Infinity thats when you use L'Hopital's rule.

For the first one you can use the rule immediately. For the second one you have to get it in the form Infinity/Infinity so you get a common denominator and it turns into -5x/(x+5), and then use the rule. - Dec 18th 2008, 09:23 PMSoroban
Hello, Moon!

Quote:

Quote:

Divide top and bottom by

. .

- Dec 18th 2008, 09:41 PMChris L T521
See this post, and read my generalization for limits of rational expressions (note this is just for . You can make slight modifications for it as it goes to ).