Simple multivariable problem w/ ellipse

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SUMMARY

The discussion focuses on calculating the derivative du/dx for the function u = x^3 + 3xy + y^3 constrained by the ellipse equation 2x^2 + 3y^2 = 1. The solution involves using the chain rule, expressed as du/dx = ∂u/∂x + ∂u/∂y * dy/dx. To find dy/dx, participants must differentiate the ellipse equation implicitly, leading to the necessary relationship between x and y for the derivative calculation.

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  • Understanding of partial derivatives
  • Familiarity with the chain rule in calculus
  • Knowledge of implicit differentiation
  • Basic concepts of ellipses and their equations
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  • Learn about the application of the chain rule in multivariable calculus
  • Explore examples of derivatives constrained by geometric shapes
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Students studying multivariable calculus, particularly those tackling problems involving derivatives constrained by geometric equations, as well as educators seeking to clarify these concepts.

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Homework Statement



If u=x^3 + 3xy + y^3, determine du/dx on the ellipse 2x^2+3y^2=1

2. The attempt at a solution

Imagine I just use partial derivative somehow, but I'm not sure what the question is asking by on the ellipse. I have a feeling its just something simple that I'm overlooking. Any help is appreciated. Thanks
 
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The chain rule:
[tex]\frac{du}{dx}= \frac{\partial u}{\partial x}+ \frac{\partial u}{\partial y}\frac{dy}{dx}[/tex]
You get dy/dx from the requirement that [itex]2x^2+ 3y^2= 1[/itex], of course.
 

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