Partial differential
of the first order of a function in several variables
The differential of the function with respect to one of the variables, keeping the remaining variables fixed. For example, if a function is defined in some neighbourhood of a point , then the partial differential of with respect to the variable at the given point is equal to the ordinary differential at of the function in the single variable , i.e.
It follows that
Partial differentials of order are defined analogously. For example, the partial differential of order of with respect to at is just the -th order differential of the function in the single variable at the point . Hence,
Comments
For references see Differential calculus and Differential.
Partial differential. Encyclopedia of Mathematics. URL: http://encyclopediaofmath.org/index.php?title=Partial_differential&oldid=48133