## Area Functions

An area function ƒ(x, y) is plotted, i.e. the three-dimensional diagram of a function with two
variables. In many area functions, terms are used several times; therefore it is possible to define
a term u(x, y) separately and to use it as a u in the function term.

### Examples:

a) ƒ(x, y) = sin(u) / u

u(x, y) = sqr(x * x + y * y)

-8 ≤ x ≤ 8

-8 ≤ y ≤ 8;

-0,5 ≤ z ≤ 1,5

b) ƒ(x, y) = abs(sin (x)) + abs(cos (x))

1 ≤ x ≤ 8;

1 ≤ y ≤ 8;

0 ≤ z ≤ 2

### See also:

Supported Functions
Adjusting the Coordinate System