What values of m as a function of q satisfy this trigonometric equation?

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Discussion Overview

The discussion revolves around finding values of m as a function of q that satisfy the trigonometric equation 2\sin \left ( \frac{q\pi }{m} \right )-\sin \left ( \frac{q\pi }{2} \right )=0. The scope includes mathematical reasoning and exploration of trigonometric identities.

Discussion Character

  • Exploratory, Mathematical reasoning, Debate/contested

Main Points Raised

  • One participant presents a trigonometric equation and suggests that both terms being zero (q=2n; m=2) is an obvious solution, but notes there are more solutions to explore.
  • Another participant questions whether q and m are integers, seeking clarification on the nature of the variables.
  • A different participant clarifies that both q and m are intended to be continuous for their purposes.
  • One participant points out that an expression for m as a function of q has been found and suggests adding +2 pi * k to obtain additional solutions for m.
  • Another participant expresses doubt about the possibility of finding a simpler expression involving q, m, π, and possibly n without trigonometric functions.
  • A later reply expresses surprise at the suggestion of a simpler expression existing.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the existence of a simpler expression for m in terms of q without trigonometric functions, and there are differing views on the nature of the variables involved.

Contextual Notes

The discussion includes uncertainty regarding the simplification of the expression for m and the conditions under which the variables q and m are defined.

LmdL
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I have a trigonometric equation
2\sin \left ( \frac{q\pi }{m} \right )-\sin \left ( \frac{q\pi }{2} \right )=0
and want to know what values m as a function of q could take to satisfy the equation. Both terms zero is the obvious solution: q=2n; m=2; n is an integer. But there are more solutions. I tried to use different kinds of trigonometric identities, with no luck.
The best I could get is
m=\frac{q\pi}{\arcsin \left ( \frac{1}{2}\sin \left ( \frac{q\pi }{2} \right ) \right )}
which for q=2n gives q/m is an integer.
Is there a more elegant general solution?

Thanks!
 
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Are q and m integers?
 
In general, for my purpose, both are continuous.
 
You found an expression of m as function of q. What else do you need?
You can add +2 pi * k at a suitable place (where you take the arcsine) to get the other solutions for m.
 
I'm in doubt if there is a simpler expression involving q,m,π and probably n (integer). Without trigonometric functions.
 
That would surprise me.
 

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