ABSTRACT

Ordinary differential equations may be solved, in some circumstances, using a method of separation of variables. This involves collecting terms

involving like variables and integrating. If the differential equation can be expressed in the form:

then the solution is found by integrating to give:

(first order equation)

A function f(x,y) is said to be homogeneous and of degree n if for some value of k:    

yxfkkykxf n ,,  For example:

Homogeneous of degree 2

C id h fi d diff i l i b l h M( ) d N( )

Homogeneous of degree 0

ons er t e rst or er erent a equat on e ow w ere x,y an x,y are both homogeneous and of the same degree:

Homogeneous of degree 0

,Now,

because homogeneous

The first equation can thus be expressed in the form:

Putting y = vx, where v is a new variable, we have an equation in which the variables are separable.