If a function 
has a pole at 
, then the negative power part
 |
(1)
|
of the Laurent series of 
about 
 |
(2)
|
is called the principal part of 
at 
. For example, the principal part of
 |
(3)
|
is 
(Krantz 1999, pp. 46-47).
Principal Part
See also
Laurent Polynomial, Laurent SeriesExplore with Wolfram|Alpha
References
Krantz, S. G. "Principal Part of a Function." §4.3.1 in Handbook of Complex Variables. Boston, MA: Birkhäuser, pp. 46-48, 1999.Referenced on Wolfram|Alpha
Principal PartCite this as:
Weisstein, Eric W. "Principal Part." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/PrincipalPart.html