What is the Limit to Infinity of a Rational Function?

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SUMMARY

The limit of the rational function lim_x->∞ of [√x + 2|x|] / [1 + x] evaluates to ±2. The user correctly divided the numerator and denominator by the highest power of x, simplifying the expression to [x^-1/2 +/- 2] / [1/x + 1]. As x approaches infinity, the limit simplifies to [0 +/- 2] / [0 + 1], confirming that the limit is indeed ±2, with the clarification that x is positive as it approaches +∞.

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Homework Statement



lim_x->∞ of [√x + 2|x|] / [1 + x]

Homework Equations


lim_x->∞ of 1/[x^n] = 0


The Attempt at a Solution


Hi everyone,

Here's what I've done so far:

I divided top and bottom by the highest power of x, i.e. x.
So:
[x^-1/2 +/- 2] / [1/x + 1]

And taking the limit of x to ∞ of this:
[0 +/- 2] / [0 + 1] = +/- 2

Is this correct?

Thanks for any help.
 
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Why is there a \pm in your answer?...Surely you recognize that x is positive as it approaches +\infty?
 
gabbagabbahey said:
Why is there a \pm in your answer?...Surely you recognize that x is positive as it approaches +\infty?

Thanks, I didn't think about that. But is it correct apart from that?
 
Yes.
 

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