Exact and Inexact Differential

FourierX
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Homework Statement



Is (x2 -y)dx + xdy = dF an exact differential ?

dF = path dependant ( i.e. d has a line strikethrough it as h in Planck's constant.)


Homework Equations



(x2 -y)dx + xdy = dF

The Attempt at a Solution



I don't know what exact and inexact differentials are. Please help me.
 
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Hi FourierX! :smile:

Exact differential means that the left hand side is exactly d(something), for example y2cosxdx + 2ysinxdy is an exact differential because it is d(y2sinx)
 
Mdx + Ndy = f(x) is exact only when this condition is met \frac{\partial M}{\partial y} = \frac{\partial N}{\partial x} (It has to be EXACTLY equal...no minus signs allowed etc..)
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...

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