Integration by parts possible?

In summary, the integral of 1/[(x^2+1)(x+1)] can be solved using the method of partial fractions. Using this method, the integral can be broken down into simpler fractions, making it easier to solve. However, in the context of a test where this question is positioned as an "integration by parts question," it may be necessary to use the method for rational functions with all coefficients.
  • #1
Krappy
16
0

Homework Statement



Calculate:

[tex]\integral \frac{1}{(x^2+1)(x+1)}[/tex]


Homework Equations



[tex]\integral f(x) g'(x) = f(x) g(x) - \integral f'(x) g(x) + C[/tex]

The Attempt at a Solution



I've tried using both [tex]1/(x+1)[/tex] and [tex]1/(x^2 + 1)[/tex] as [tex]dv[/tex], but both end up in another integral I can't solve, one with [tex]-ln(x+1) 2x / (x^2+1)^2[/tex] and the other with [tex]-atan(x)/(x+1)^2[/tex].

I think that probably this can only be solved with the method for rational functions (with all the coefficients), but I'm not sure.
 
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  • #2
Using partial fractions is much better idea.
 
  • #3
Dick said:
Using partial fractions is much better idea.

Thanks for answering. I know it's much better, but I'm solving some tests (same format) and the position in which this one appears is the "integration by parts question".
 

1. Is integration by parts possible for all functions?

Yes, integration by parts is possible for all functions as long as the integral can be broken down into a product of two functions.

2. What is the purpose of using integration by parts?

The purpose of using integration by parts is to simplify the integral by breaking it down into smaller, easier to integrate parts. This can be especially useful when dealing with complex integrals.

3. How do I know when to use integration by parts?

Integration by parts can be used when the integral involves a product of two functions or when the integral is in the form of uv.

4. What happens if I choose the wrong function for integration by parts?

If the wrong function is chosen for integration by parts, the resulting integral may be more complex and difficult to solve. It is important to carefully select the functions to ensure the integral is simplified.

5. Can integration by parts be used to solve definite integrals?

Yes, integration by parts can be used to solve definite integrals. The same rules apply, but the limits of integration must also be taken into consideration.

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