$\displaystyle \frac{-1}{\sqrt{x+1}}$ how is it possible calculate the residue bout x=-1 and do the laurent series about of x=-1 thanks,
Unfortunately the function $\displaystyle f(z)=- \frac{1}{\sqrt{1+z}}$ has in z=-1 a brantch point, so that the Laurent series around z=-1 doesn't exist...