more than 1 function with Plot3D

*To*: mathgroup at smc.vnet.net*Subject*: [mg50613] more than 1 function with Plot3D*From*: "Ron" <ronhaus at arcor.de>*Date*: Mon, 13 Sep 2004 02:19:26 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

Hi, I would like to plot the functions u(x1,x2) = (x1+20)*x2 (main function) ->Nutzenfunktion 20 = 2x1 + x2 ->Budgetgeraden 60 = 2x2 + x2 ->Budgetgeraden 800 = (x1+20)*x2 -> Indifferenzkurve (Volkswirtschaftslehre VWL) Is it somehow possible, I'd like to have all functions in one graph. So far: Plot3D[(a + 20)b, {a, 0, 30}, {b, 0, 30}, AxesLabel -> {"x1", "x2", "Nutzen"}] THX