Homogeneous Functions

The polynomial function, where the degree of each term is n and

f(x,y) = a0xn + a1 xn-1 + a2xn-2y2 +…….+ anyn

is called a homogeneous function of degree n x and y. Again.

f(x,y) = a0xn + a1 xn-1 + a2xn-2y2 +…….+ anyn

= xn [a0 + a1 (y/x) + a2 (y/x)2 +…..+ + an(y/x)n]

= xnf(y/x)

Thus, a function f(x,y) is said to be homogeneous function of degree n in x and y, if

f(x,y) = xn f(y/x)

Definition:

A function z = f(x,y) is said to be homogeneous of degree n (n being a constant) if, for any

real number λ

F(λ× , λy ) =  λn f(x,y)

Thus, if both x and y are multiplied by the same real number, then the resulting function value is a power of the number times the function value f(x,y).

Example : If f(x, y) = 2x2y+ xy2 – y3

F(λ× , λy ) = 2( λx)( λx) + (λx) (λy)-(λy)3

=2λ³x2y+ λ³xy– λ³y3 

= λ³f(x,y)