Taking Differentials to Find Partial Derivative

[jamjar]

Hi,
I'm trying to take differentials of the following equation

(p + \frac{a}{{V^2 }})(V - b) = C

in order to find the partial derivative \frac{{\partial p}}{{\partial V}}

I know there's an easier way to do it but I have to take differentials.
I'm just not sure how to deal with the brackets without multiplying out (I can't rearrange the equation).

Any hints welcome.

 

[HallsofIvy]

Use the product rule!

 

[jamjar]

How do I do that with differentials?
I end up with crazy results.

 

[Physics Monkey]

You "can't" rearrange the equation, as in the problem won't let you? The product rule for differentials is d(fg) = g df + f dg.

 

[jamjar]

If I use that product rule I end up with a free floating p in my equation where I know that \frac{{\partial p}}{{\partial V}} doesn't have a term in p

 

[Physics Monkey]

Yes, you then have to solve for p in terms of V using the original equation. This I why I don't undestand why you can't just solve for p in terms of V from the start since you have do it eventually anyway.