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How to integrate int -1/(x^2 +1)^2 dx

  • Thread starter cscott
  • Start date
783
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1. Homework Statement

Find the following intergral...

2. Homework Equations

[tex]\int{\frac{-1}{(x^2+1)^2}dx}[/tex]

3. The Attempt at a Solution

I can't get anywhere with this... any hints?
 
Last edited:
492
1
sorry rushed the problem and did it wrong
 
Last edited:
57
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hint:

[tex] \frac{d}{{dx}}{\arctan{x}} = \frac{1}{x^2 +1} [/tex]
 
Last edited:

StatusX

Homework Helper
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Try adding and subtracting x^2 in the numerator.
 

dextercioby

Science Advisor
Homework Helper
Insights Author
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Make the substitution [itex] x=\tan t [/itex]. You'll eventually get [itex] \int \cos^2 t \ dt [/itex] which is easy to do.

Daniel.
 

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