Exact Sin Calculus: Solving for Trigon Funcs Without Triangles

  • Context: Graduate 
  • Thread starter Thread starter vjacheslav
  • Start date Start date
  • Tags Tags
    Calculus Sin
Click For Summary

Discussion Overview

The discussion revolves around the exact calculus of trigonometric functions without relying on triangles. Participants explore the limitations of conventional methods used in calculators and computer programming for calculating sine and cosine values, and seek alternative definitions or algorithms.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • One participant expresses concern that standard methods for calculating sine and cosine (using x for sine and x^2/2 for cosine) are insufficient and seeks a definition that does not involve triangles.
  • Another participant questions the clarity of the initial post and requests a better explanation of the problem being presented.
  • A different participant suggests that calculators and computers likely use multiple terms to compute sine and cosine values, noting that the initial terms of a Taylor series may not converge quickly enough for practical use.
  • One participant references the CORDIC algorithm as a basic method for calculating trigonometric and hyperbolic functions, highlighting that modern processors often have built-in microcode for these calculations.

Areas of Agreement / Disagreement

Participants do not appear to reach a consensus on the initial problem statement, with some seeking clarification while others provide insights into computational methods. Multiple competing views on the calculation of trigonometric functions are present.

Contextual Notes

There are limitations in the initial problem statement, particularly regarding the assumptions made about the sufficiency of current methods and the definitions of trigonometric functions without triangles. The discussion also touches on the historical context of computational methods.

vjacheslav
Messages
15
Reaction score
0
Hi!
While computer programming Us encountered problem of exact calculus of trigonometry funcs.
As is well known, all calculators and comp progs do x for Sin
and x^2/2 for Cos on 0..Pi/2 and so on. It seems insufficient.
While solving - next problem:
trigon func definition without triangle.
 
Mathematics news on Phys.org
vjacheslav said:
Hi!
While computer programming Us encountered problem of exact calculus of trigonometry funcs.
As is well known, all calculators and comp progs do x for Sin
and x^2/2 for Cos on 0..Pi/2 and so on. It seems insufficient.
While solving - next problem:
trigon func definition without triangle.

I'm sorry, but this doesn't make a lot of sense. Can you explain it better?
 
I think you may be thinking of how a calculator/computer generates the sin/cosine of a number.
They will use several terms to calculate the value.
I don't think it will be the first few terms of a Taylor series for the function - the convergence is likely to be too slow. The only case I recall is the sine function in the Fortran library for a Univac 1108. This used a fifth degree expression in x2 - I don't remember the coefficients.
 
This article describes one basic algorithm which can be used to calculate trigonometric and hyperbolic functions on relatively primitive computers:

http://en.wikipedia.org/wiki/CORDIC

Many of the processors nowadays have microcode for calculating trig functions built into the CPU itself.
 

Similar threads

  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 5 ·
Replies
5
Views
5K
  • · Replies 3 ·
Replies
3
Views
4K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 6 ·
Replies
6
Views
4K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 10 ·
Replies
10
Views
3K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 2 ·
Replies
2
Views
4K