Maximizing Integration Efficiency: Long Division vs Partial Fractions

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    Division Integrals
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Homework Help Overview

The discussion revolves around the integration of a rational function, specifically the integral of (2x+1) divided by the product of two quadratic expressions. Participants are exploring different methods for simplifying the integral.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the merits of using long division versus partial fractions for the integration process. Some question the appropriateness of long division when the degree of the numerator is less than that of the denominator. Others suggest factoring the denominator instead of expanding it.

Discussion Status

There is a clear inclination towards using partial fractions as a preferred method for this integral. Participants are actively questioning the rationale behind using long division and exploring the implications of the degrees of the polynomials involved.

Contextual Notes

Participants note that the original poster's approach of foiling the denominator may not be necessary and that the degrees of the polynomials play a crucial role in determining the method of integration.

Cacophony
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Homework Statement


∫(2x+1)/(x²+2x+1)(x²+x+1)


Homework Equations


none


The Attempt at a Solution


I've foiled this out to look like:

∫(2x+1)/(x^4+3x³+4x²+3x+1)

I'm trying long division here but it's getting really ugly really fast. Should I foil this out in the first place or should I use a different approach?
 
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I would try a different approach.

Look at the denominator and see if it can be factored rather than multiplied together.
 
Cacophony said:
I've foiled this out to look like:

∫(2x+1)/(x^4+3x³+4x²+3x+1)

I'm trying long division here but it's getting really ugly really fast. Should I foil this out in the first place or should I use a different approach?
Why would you try long division? You are dividing something "smaller" into something "bigger". It is as if you are suggesting that to evaluate \frac{7}{584} you divide 584 by 7.

Have you considered using partial fractions to split the integral into two?
 
Definitely do partial fractions. The only time you do long division is when the degree on top is bigger than the bottom.
 
iRaid said:
Definitely do partial fractions. The only time you do long division is when the degree on top is bigger than the bottom.
Or when the degrees are equal.
 

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