Infinite Degree Polynomials: Describing by Roots

Click For Summary
Infinite degree polynomials cannot be universally described by their roots like finite degree polynomials due to the existence of infinite degree polynomials without roots, such as the power series for e^x. However, certain infinite degree polynomials, like the power series for sin(x), may be factored using their roots, exemplified by the infinite product representation. The discussion highlights that what is often referred to as infinite degree polynomials are actually power series. If a power series has a meromorphic analytic continuation, it can be described using a general factorization theorem. Understanding these distinctions is crucial for accurately discussing infinite degree polynomials and their properties.
foxjwill
Messages
350
Reaction score
0

Homework Statement


Is it possible to describe some infinite degree polynomials by their roots in a way analagous to finite degree polynomials?


Homework Equations





The Attempt at a Solution



I know that, since not all infinite degree polynomials have roots (e.g. the power series representation of e^x), it would not be possible to do so for all of them. But what about polynomials like the power series of sin(x)? I was thinking maybe

\prod^\infty_{n=0} \left ( x^2 - n^2\pi^2 \right )
 
Physics news on Phys.org
Is it possible to describe some infinite degree polynomials...
There's no such thing as an infinite degree polynomial. I presume you mean a power series.

If (the analtyic continuation) of your power series is actually meromorphic, then there is a general factorization theorem. See:

http://en.wikipedia.org/wiki/Infinite_product
 
Question: A clock's minute hand has length 4 and its hour hand has length 3. What is the distance between the tips at the moment when it is increasing most rapidly?(Putnam Exam Question) Answer: Making assumption that both the hands moves at constant angular velocities, the answer is ## \sqrt{7} .## But don't you think this assumption is somewhat doubtful and wrong?

Similar threads

  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 14 ·
Replies
14
Views
2K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 4 ·
Replies
4
Views
4K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 13 ·
Replies
13
Views
2K