Exploring functions of 2 variables

Enter your function in the edit field to see its graph. You can use the provided parameters: a, b, c, h in your input, and then change their values with sliders. You have access to vertical traces of the surface (check an appropriate check box). You have access to the tangent lines to those vertical traces, as well as to the tangent plane at the point (x0, y0, f(x0, y0)).