Changes

Nevertheless, the kinds of phenomenon we see in the multivariate case is very different.  Note that while it is still possible to define a limit from a direction, we don't bother to do so - unlike the one-variable case when a one-sided deriative told us half of the functions behavior at a point, in higher dimensions such a limit tells us almost nothing.  Indeed, the only kind of phenomenon that these kinds of limits are capable of describing are "point discontinuties," which can be "fixed" just be defining the function to be the limit at that point.

Nevertheless, the kinds of phenomenon we see in the multivariate case is very different.  Note that while it is still possible to define a limit from a direction, we don't bother to do so - unlike the one-variable case when a one-sided deriative told us half of the functions behavior at a point, in higher dimensions such a limit tells us almost nothing.  Indeed, the only kind of phenomenon that these kinds of limits are capable of describing are "point discontinuties," which can be "fixed" just be defining the function to be the limit at that point.

=Partial Derivatives=

=[[Derivative#Partial_derivatives|Partial Derivatives]]=

 

::::Main article: [[Derivative#Partial_derivatives]].

 

When dealing with functions of more than one variable, one has to be careful about what a "derivative" is.  The operative concept is the ''partial derivative'', which is the derivative of the function with respect to a given argument ''while holding all the other arguments constant''.  It is written like a derivative, but with a different "d" character.

When dealing with functions of more than one variable, one has to be careful about what a "derivative" is.  The operative concept is the ''partial derivative'', which is the derivative of the function with respect to a given argument ''while holding all the other arguments constant''.  It is written like a derivative, but with a different "d" character.