Alternative First-order First-degree Differential Equation

A first-order first-degree differential equation if of the formA first-order first-degree differential equation if of the form

The equation (1) can be rewritten as

….(2)

where

So,

The fact that, Dy - f(x, y) Dx ® 0 as Dx ® 0 is expressed by writing

dy = f(x,y)dx ....(3)

is an alternative form of the differential equation (1).