Is there a way to prove the quotient rule using differentials

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The discussion focuses on proving the quotient rule for derivatives using a method similar to Leibniz's approach for the product rule. The user attempts to derive the formula for the derivative of the function y = u/v, leading to the expression Δy = (vΔu - uΔv)/(v² + vΔv). The challenge arises when the term vdv appears in the denominator as Δx approaches zero, indicating a misunderstanding of the limit process. The conversation highlights the importance of correctly applying limits in differential calculus.

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Specifically, how do you prove the quotient rule using a similar method that Leibniz used for the product rule?: http://en.wikipedia.org/wiki/Product_rule#Discovery_by_Leibniz

I've tried it once for d(u/v) but I keep getting a vdv term in the denominator.
 
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y= u/v

when you have

\Delta y = \frac{v \Deltau - u \Deltav}{v^2 +v \Delta v}

\frac{\Delta y}{\Delta x} = \frac{v \frac{\Delta u}{\Delta x} - u \frac{\Delta v}{\Delta x}}{v^2 +v \Delta v}

as Δx→ 0, Δv→ 0
 
d'oh, didn't think about vdv as dv approaches zero

thanks!
 

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