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#### Petrus

##### Well-known member

- Feb 21, 2013

- 739

I got stuck on this integrate

\(\displaystyle \int_0^{\infty}\frac{2x-4}{(x^2+1)(2x+1)}\)

and my progress

\(\displaystyle \int_0^{\infty} \frac{2x-4}{(x^2+1)(2x+1)} = \frac{ax+b}{x^2+1}+ \frac{c}{2x+1}\)

then I get these equation that I can't solve

and I get these equation..

\(\displaystyle 2a+c=0\) that is for \(\displaystyle x^2\)

\(\displaystyle 2b+a=2\) that is for \(\displaystyle x\)

\(\displaystyle b+c=-4\) that is for \(\displaystyle x^0\)

What have I done wrong?

Regards,

\(\displaystyle |\pi\rangle\)