Maximizing Gamma with Lagrange Multipliers

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Discussion Overview

The discussion revolves around maximizing the variable gamma ($\gamma$) using the method of Lagrange multipliers, with a focus on the constraints provided by two equations related to a physical system. The scope includes mathematical reasoning and technical explanation regarding optimization techniques in the context of physics.

Discussion Character

  • Mathematical reasoning, Technical explanation, Debate/contested

Main Points Raised

  • One participant presents the equations and asks whether they need to solve for gamma to apply Lagrange multipliers.
  • Another participant outlines the objective function and constraints, suggesting the use of a second multiplier, $\beta$, instead of $\mu$, which is one of the variables.
  • This participant provides a system of equations derived from the Lagrange multipliers method, indicating the need to draw implications regarding the variables.
  • A third participant claims to have found an easier method to approach the problem, though details are not provided.
  • A fourth participant expresses relief that the previous method seemed complex, indicating a preference for simpler approaches.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the best method to maximize gamma, with differing opinions on the complexity of the approaches and at least one participant suggesting an alternative method.

Contextual Notes

The discussion includes assumptions about the variables and constraints, but does not resolve the implications drawn from the system of equations presented. The effectiveness of the proposed methods remains uncertain.

Dustinsfl
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Given the equations
$$
rv\cos\gamma - h = 0,\quad \frac{v^2}{2} - \frac{\mu}{r} + \frac{\mu}{2a} = 0
$$
I want to maximize gamma.
Do I have to solve for gamma in the first equation to use the method of Lagrange multipliers, or if not, how would I do this in the current form?
 
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Re: Langrange multipliers

If I understand correctly, we have 6 variables, 2 constraints, and the objective function.

The objective function is:

$f(a,h,r,v,\gamma,\mu)=\gamma$

subject to the constraints:

$g(a,h,r,v,\gamma,\mu)=rv\cos(\gamma)-h=0$

$h(a,h,r,v,\gamma,\mu)=\dfrac{v^2}{2}-\dfrac{\mu}{r}+\dfrac{\mu}{2a}=0$

Normally, we use a multiplier for each constraint, and $\lambda$ and $\mu$ are used, but since $\mu$ is one of our variables, would may choose another, such as $\beta$ to be the second multiplier.

So, what we would wind up with is:

$\displaystyle 0=\lambda(0)+\beta\left(-\frac{\mu}{2a^2} \right)$

$\displaystyle 0=\lambda(-1)+\beta(0)$

$\displaystyle 0=\lambda(v\cos(\gamma))+\beta\left(\frac{\mu}{r^2} \right)$

$\displaystyle 0=\lambda(r\cos(\gamma))+\beta(v)$

$\displaystyle 1=\lambda(-rv\sin(\gamma))+\beta(0)$

$\displaystyle 0=\lambda(0)+\beta\left(-\frac{1}{r}+\frac{1}{2a} \right)$

Now, from this system, you need to draw out implications regarding the variables.
 
Re: Langrange multipliers

I found an easier way to do it though.
 
Re: Langrange multipliers

Good, because what I posted did not look like any fun at all! (Yes)
 

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