How do you find the zeroes of a discrete function?

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Discussion Overview

The discussion revolves around finding the zeroes of a specific discrete function defined as y = 40sin(2x) - floor(40sin(2x)). Participants explore various methods, including Newton's method, to approach the problem and share insights on the nature of the function and its zeroes.

Discussion Character

  • Exploratory
  • Mathematical reasoning
  • Homework-related

Main Points Raised

  • One participant suggests using Newton's method to find the zeroes of the function, noting that it equals zero when 40sin(2x) is an integer.
  • Another participant expresses uncertainty about how to handle the problem and asks for more context regarding the class or similar problems encountered.
  • A later reply indicates that the problem is similar to solving frac{40sin(2x)} = 0.
  • One participant mentions breaking the function into separate segments defined as linear to facilitate the use of an iterated Newton method.
  • Another participant questions the origin of the problem and requests clarification on the method used.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the best method to find the zeroes, and multiple approaches are discussed without resolution.

Contextual Notes

Participants express uncertainty about the distribution of integers resulting from the function and the concept of an inverse-floor function. There is also a lack of clarity regarding the context in which the problem arose.

Who May Find This Useful

Readers interested in mathematical methods for finding zeroes of functions, particularly in the context of discrete functions and numerical methods, may find this discussion relevant.

Frogeyedpeas
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Would Newton's method or some other method work? Consider the following problem:

find the zeroes of the function: y = 40sin(2x) - floor(40sin(2x))

where Y,X \in R

I don't exactly know how to handle this problem. My best insight so far is that it is only equal to zero whenever 40sin(2x) is an integer. But even then the distribution of these integers is quite random and I honestly don't know any inverse-floor function.
 
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Frogeyedpeas said:
Would Newton's method or some other method work? Consider the following problem:

find the zeroes of the function: y = 40sin(2x) - floor(40sin(2x))

where Y,X \in R

I don't exactly know how to handle this problem. My best insight so far is that it is only equal to zero whenever 40sin(2x) is an integer. But even then the distribution of these integers is quite random and I honestly don't know any inverse-floor function.
Could you tell us a little more about what class this is from, and what kind of similar problems you may have encountered, and tell us a little about the techniques you're class us covering?
 
ehhh not exactly from a class (sorry), and I don't have any sample problems for this thing either. It just kind of came up. My best guess is to use Newton's formula.

I mean Newton's method
 
Last edited:
So this problem i basically the same thing as frac{40sin(2x)} = 0.
 
w8 nvm I'm good, I got the method
 
So what was the method? Where did the problem come up?
 
Well it turns out if you do an iterated Newton method the number works. To speed things up i broke up the function into separate segments defined as linear. The function appeared out of the context of being given a discrete function how do you make a contonuous analog
 

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