Analytic Function with a Pole at 1

In summary, an analytic function is a mathematical function that is defined and continuous in a given region of the complex plane, with derivatives of all orders at each point within that region. A pole in an analytic function is a point where the function is undefined or infinite, and can cause the function to have discontinuities. To find the location of a pole, the equation of the function needs to be solved to determine the values that make the function undefined or infinite. There is a difference between a simple pole and a multiple pole, with a simple pole having an order of 1 and a multiple pole having an order greater than 1. Poles can affect the behavior of an analytic function by causing discontinuities, influencing the convergence of a
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Homework Statement



Let r>1, let f be analytic in the disc (0,r)\{1}, and suppose that f has apole at 1.

Let sum(a(k) *z(k)) be the power series expansion of f in the disc (0,r). Prove that there is a positive integer N so that a(k) not equal to zero for k>= N, and that

lim (a(N+j+i)/a(N+1))=1


Homework Equations





The Attempt at a Solution

 
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no body replied on this problem

is it so hard?
 

FAQ: Analytic Function with a Pole at 1

What is an analytic function?

An analytic function is a mathematical function that is defined and continuous in a given region of the complex plane. It also has derivatives of all orders at each point within that region.

What is a pole in an analytic function?

A pole in an analytic function is a point where the function is undefined or infinite. It is usually represented as a singularity in the complex plane and can cause the function to have discontinuities.

How do you find the location of a pole in an analytic function?

To find the location of a pole in an analytic function, you need to solve the equation of the function to determine the values that make the function undefined or infinite. These values will correspond to the location of the poles in the complex plane.

What is the difference between a simple pole and a multiple pole?

A simple pole is a point where the function has a single pole, while a multiple pole is a point where the function has more than one pole. The order of a pole refers to the number of poles at a given point, with a simple pole having an order of 1 and a multiple pole having an order greater than 1.

How can poles affect the behavior of an analytic function?

Poles can cause the function to have discontinuities, making it non-analytic at those points. They can also affect the convergence of a power series representation of the function, and the location of poles can provide valuable information about the behavior of the function in the complex plane.

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