Domain and Range

Problem:

Find the Domain D and Range R for the function,

> f := (x,y) -> sqrt(x-y);

Clearly this function is defined where the square root is defined, i.e. for all non negative real numbers. D = {(x,y) : x >= y}

The range is the set of values that f(x,y) can take. We have,

R = {z : z >= 0} since f(x,y) is defined as the POSITIVE square root of (x-y).

Last modified: Wed Mar 21 12:25:44 EST 2001