(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Apologies if this doesn't come through properly.

The question states

Use a change of time variable to show that the equation

[tex]c(\tau) \frac{\partial u}{\partial \tau} = \frac{\partial^2 u}{\partial x^2}[/tex]

can be reduced to the diffusion equation.

3. The attempt at a solution

I've tried a couple of things, primarily setting up

[tex]v(\tau) = \int c(\tau)[/tex]

in the hope that the product rule would give me something to cancel out on the left hand side, but no luck. I'm pretty certain this is going to be one of those nasty little mathematical tricks that can be described in six words or less. If anybody wants to give me a pointer as to what I should be looking for, it would be appreciated.

Thanks.

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# Diffusion Equation/Change of Variable

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