technique for computing residues


The following two facts are quite useful for computing residues:

If f has a pole of order at most n+1 at x, then

Res(f;x)=limyx1n!dndyn((y-x)n+1f(y)).

If g is regular at x and f has a simple poleMathworldPlanetmathPlanetmath at x, then Res(fg;x)=g(x)Res(f;x).

Title technique for computing residues
Canonical name TechniqueForComputingResidues
Date of creation 2013-03-22 16:20:11
Last modified on 2013-03-22 16:20:11
Owner rspuzio (6075)
Last modified by rspuzio (6075)
Numerical id 7
Author rspuzio (6075)
Entry type Theorem
Classification msc 30D30
Related topic CoefficientsOfLaurentSeries
Related topic ResiduesOfTangentAndCotangent