ABSTRACT
This chapter looks at some applications of partial differentiation, i.e. the total differential for variables which may all be changing at the same time, rates of change, where different quantities have different rates of change, and small changes, where approximate errors may be calculated in situations where small changes in the variables associated with the quantity occur. it helps the reader to determine the total differential of a function having more than one variable. The chapter helps the reader to determine the rates of change of functions having more than one variable.It also help the reader to determine an approximate error in a function having more than one variable. It is often useful to find an approximate value for the change of a quantity caused by small changes in the variables associated with the quantity.
