Complex contour integral - branch cut

[Batzo]

Im trying to understand the contour when there are two poles on the real axis without poles on Im axis, because their residue cancle each other.

For residue of pole(-2)=-1, residue of pole(-1)=-1:

$$I=\int_0^\infty\frac{dx}{(x+1)^2(x+2)}$$

 

[nasi112]

residue of $\displaystyle x = -2$ is $\displaystyle 1$

 

[Batzo]

Yes sorry. The minus is there by an accident.
I cant rewrite the post...
Still,how do I solve it?

 

[blamocur]

Im trying to understand the contour when there are two poles on the real axis without poles on Im axis, because their residue cancle each other.

For residue of pole(-2)=-1, residue of pole(-1)=-1:

$$I=\int_0^\infty\frac{dx}{(x+1)^2(x+2)}$$

What exactly do you have to solve? To compute the integral? Something else?

 

[Batzo]

What exactly do you have to solve? To compute the integral? Something else?

Yes, computing the integral using branch cut method.