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Complex series Numerical Series1) convergent Series : The series says convergent if the succession {S n} ofits partial sums is convergent, in such case the S limit of the succession {Sn} says sum of the series .
2) Rest n-esimo of the series: Draft of the series .
3) Criterion of convergence of Cauchy : The series is convergent > " and > 0 a N index can be found such that per n ³N.
4) absolutely convergent Series : If the series to real terms then is convergent also the series that in this case is said absolutely convergent.
5) Criterion of convergence of Of Alembert : The series is convergent if, beginning from a N index, is worth the relation " n ³ N.
6) Criterion of convergence of Cauchy : The series is convergent if, beginning from a N index, is worth the relation " n ³ N. Series of functions7) punctual Convergence : The series of functions says convergent in its dominion if the numerical series to relative it converges " z that is if " z and for every positive number and a N index can be found such that for n > N .
8) uniform Convergence : The series of functions uniform says convergent in its dominion if the numerical series to relative it converges " z that is if " positive number and can be found a N(indexand) such that " n > N(and), every for z pertaining to the dominion.
9) Criterion of Weierstrass of convergence total: If in a dominion the modules of the terms of the series of functions are increased ovunque from the terms of an absolutely convergent numerical series the series it converges uniform in its dominion.
10) Criterion of Cauchy : Necessary and sufficient condition for the uniform convergence of the series is that " and > 0 a N(existsand) such that the relation is verified simultaneously in all the points of the dominion for n ³ N and " m.
11) Theorem of Weierstrass on the property of the uniform convergent series : If the functions un(z) are continuous in u dominion and if the series converges uniform in this dominion to the function f(z) also f(z) it is continuous in the same dominion.
12) Theorem of Abel or Cauchy - Hadamard: If the series of powers converges in a point z1 ¹ z0 , it converges absolutely also in a such point z that |z-z0| < |z1 - z0| ; moreover the series converges uniform in every circle |z-z0| £ r of beam r < |z1 - z0|. Being the convergent series in z1 then its terms stretch to the zero for n®¥ therefore general term can that is be increased from one constant M and therefore is had but we are interested to see if the series for a such point converges absolutely z that |z-z0|<|z1 - z0| therefore we take the module of the series of powers but this last one is a geometric series of reason q<1 and therefore the given series is convergent therefore for the criterion of the comparison converges absolutely. In order to demonstrate the uniform convergence the criterion of Weierstrass is used that previews the maggiorazione with a convergent numerical series which as an example it can be r < |z1 - z0| .
13) convergent series of powers to f(z) Is one in the circle of convergence D(z0 , R) f(z) is analytics and f ' (z) =
14) Theorem of the passage of the limit under the sign of integral: Given one series of uniform convergent continuous functions and to u(z) in a D dominion " at times contained regular G curve in D is had It observes itself that the difference between the two integrandi is equal to the rest n-esimo and being the convergent series uniform, can that is be increased where L is the length of the curve along which integral, therefore is had and therefore there is the equality between the two terms. |