How Do I Solve This Integral with Completing the Square and Long Division?

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Homework Help Overview

The discussion revolves around solving an integral that involves completing the square and long division. Participants are exploring various methods to tackle the integral, which appears to involve polynomial expressions.

Discussion Character

  • Mixed

Approaches and Questions Raised

  • The original poster attempts to complete the square and has also tried long division, expressing difficulty with the latter part of the integral. Some participants suggest using substitution methods, while others question the appropriateness of the original poster's approach to long division.

Discussion Status

Participants are actively engaging with the problem, offering various suggestions and methods. There is a mix of guidance on substitution and clarification on the long division process, indicating a collaborative exploration of the topic.

Contextual Notes

There are indications of confusion regarding the nature of the denominator, with some participants noting that it is a cubic expression rather than a quadratic one. This has led to discussions about the correct approach to the integral.

Fiorella
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Hello, can someone help me solve this integral? I think I need to complete the square...I've tried many other things but I don't know what else to use :confused:

integral.jpg


and

integral2.jpg


With the last one I did long division and I ended up with: x + x/ (x - 1)...so I can easily solve the first integral of X but now I can't solve the other part... :(
 
Last edited:
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Try using latex, it might be a while before we can view your image.
 


I posted the image differently :)
 


U-sub is the easiest on the first one, u-sub and factor actually...

U-sub the second one too
 


Fiorella said:
Hello, can someone help me solve this integral? I think I need to complete the square...I've tried many other things but I don't know what else to use :confused:

integral.jpg


and

integral2.jpg


With the last one I did long division and I ended up with: x + x/ (x - 1)...so I can easily solve the first integral of X but now I can't solve the other part... :(

you could rewrite

\frac{x}{(x-1)}

as

1+\frac{1}{x-1}

if that is any easier for you.
 
Last edited:


Fiorella said:
Hello, can someone help me solve this integral? I think I need to complete the square...I've tried many other things but I don't know what else to use :confused:

integral.jpg
Not "complete the square", the denominator is a cube, not a square! The substitution
u= -x3+ 9x+ 1 works nicely.

and

integral2.jpg


With the last one I did long division and I ended up with: x + x/ (x - 1)...so I can easily solve the first integral of X but now I can't solve the other part... :(
You need to review your long division! x2 divided by x- 1 is x+ 1+ 1/(x-1).
 


Thank you so much everybody :)
 

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