Partial differentiation of a function with more than one variables refers to its derivative being taken with respect to one of those variables, while the rest being held as a constant.
An example is the volume of a cylinder given by:
[tex]V(h, r) = \pi r^{2}h[/tex]
The volume requires two variables in order to work out the volume, namely the radius and the height.
Using partial differentiation, its partial derivative can become:
[tex]\frac{\partial V}{\partial r} = 2\pi rh[/tex]
This symbol is used in place of the derivative symbol, in order to distinguish total derivatives and partial derivatives.
