Differentials : In this section we will introduce a notation. We will also look at an application of this new notation.
Given a function y = f ( x ) we call dy & dx differentials and the relationship among them is specified by,
dy = f ′ ( x ) dx
Note as well that if we are just given f (x) then the differentials are df & dx and we calculate them in the similar manner.
df = f ′ ( x ) dx