A real function of three variables is created through icon of the calculations expandable bar (third from the bottom).
Such a function may be modified through icon .
For instance,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.