How do I find dy/dx for x2y+xy2=6 using implicit differentiation?

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Homework Help Overview

The discussion revolves around finding the derivative dy/dx for the equation x²y + xy² = 6 using implicit differentiation. Participants are exploring the differentiation of both sides of the equation and the subsequent algebraic manipulation required to isolate dy/dx.

Discussion Character

  • Mathematical reasoning, Problem interpretation, Assumption checking

Approaches and Questions Raised

  • Participants describe their attempts at differentiating the equation and express uncertainty about the algebraic steps needed to isolate dy/dx. There are questions regarding the correctness of the numerator in the final expression for dy/dx.

Discussion Status

The discussion is ongoing, with participants providing feedback on each other's attempts and suggesting revisiting the differentiation process. Some guidance has been offered regarding the differentiation of individual terms, but there is no explicit consensus on the final form of dy/dx.

Contextual Notes

There is a noted uncertainty about the algebraic manipulation following differentiation, particularly concerning the numerator of the expression for dy/dx. Participants are also referencing specific terms and their derivatives, indicating a focus on careful interpretation of the differentiation process.

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Homework Statement


find dy/dx for x2y+xy2=6


Homework Equations





The Attempt at a Solution


d/dx (x2y+xy2) = d/dx (6)
x2*(dy/dx)+y*2x+x*2y(dy/dx)+2y=0
x2*(dy/dx)+y*2x+x*2y(dy/dx)=-2y
(dy/dx)+y*2x+x*2y(dy/dx)=(-2y/x2)
(dy/dx)+y*2x+(dy/dx)=(-2y/x2+2xy)

I'm not sure what to do now, i know that the answer is (2xy-y2/x2+2xy)

I got the denominator correct in my answer but I'm not sure how to get the numerator correctly. Did I go wrong somewhere during the process?
 
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Now you algebraically solve for dy/dx.
 
Jim4592 said:

Homework Statement


find dy/dx for x2y+xy2=6

The Attempt at a Solution


d/dx (x2y+xy2) = d/dx (6)
x2*(dy/dx)+y*2x+x*2y(dy/dx)+2y=0
Try that again. Piece by piece:
[tex]x^2y[/tex] differentiates to [tex]2xy + x^2y'[/tex]
[tex]xy^2[/tex] differentiates to [tex]y^2 + 2xyy'[/tex]

Then follow Tom's advice!
 
Jim4592 said:
I'm not sure what to do now, i know that the answer is (2xy-y2/x2+2xy)

I got the denominator correct in my answer but I'm not sure how to get the numerator correctly.

Hi Jim4592! :smile:

Isn't it (2xy + y2/x2+2xy)?
 
tiny-tim said:
Isn't it (2xy + y2/x2+2xy)?
Rather,

-[/color](2xy + y2)/(x2 + 2xy)
 
oops! :redface:

thanks, Unco! :smile:
 

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