It is a real function of three real variable.
A real function of three variables is created through menu Calculus - New real calculation - Real function of three variables.
Such a function may be modified through icon .
For example,you ca define a real function of three variables by f(x, y, z) = 2x²yz+ 3x + z + 1. Enter f for the name, x, y and z for the variables names and 2*x^2*y+ 3*x + y + 1 for formula.
See also : Real calculus syntax.