Rational expression limit problem

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Homework Help Overview

The discussion revolves around limits of rational expressions involving polynomials, specifically focusing on cases where the degrees of the polynomials are the same or where the degree of the denominator exceeds that of the numerator. The original poster seeks to understand how to prove these limit behaviors, particularly as the variable approaches infinity.

Discussion Character

  • Exploratory, Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants discuss the conditions under which limits of rational expressions yield specific values, questioning the role of leading coefficients and polynomial degrees. The original poster expresses uncertainty about using induction for the proof.

Discussion Status

Some participants have provided clarifications regarding the limits of rational functions, particularly emphasizing the importance of leading coefficients. The conversation is ongoing, with no explicit consensus reached on the proof method or the specific limit behaviors.

Contextual Notes

The original poster mentions that this limit problem is part of a more complex issue they are working on, indicating that there may be additional constraints or considerations not fully explored in the current discussion.

StonedPanda
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Sligtly more complex than the average one, I'd assume. How would I go about proving that the limit of of a rational expression consisting of two polynomials of the same degree goes to one and the limit of one where the degree of the bottom is greater than the degree of the top goes to zero. I'd imagine i'd have to use induction, but I've never learned it!

This step is actually a step in a more complicated problem, which I've got for the most part.
 
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Limit as x approaches infinity? Consider:

2x/x

this is a rational function of two polynomials of the same degree whose limit is never 1 for any x, it is always 2. Also consider:

2(x+1)/x

again, it has a limit of 2 as x approaches infinity, but it's limit isn't always 2, for example, it is 4 when x approaches 1. Perhaps you mean when both polynomials also have the same leading coefficient. In that case, the limit as x approaches infinity will be 1.
 
yes, sorry, i meant for the case when the polynomials has the same leading coefficient as the variable approaches infinity.
 
so can anyone help me prove this? I'm trying to teach myself induction...
 

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