A real function of two variables is created through icon of the calculations expandable bar (third from the bottom).
Such a function may be modified via icon .
For instance,you can define a real function of two variables by f(x, y) = 2x²y+ 3x + y + 1. Enter f for the name, x and y for the variables names and 2x^2*y+ 3*x + y + 1 for formula.
See also : Real calculus syntax.