Computer programs are readily available for graphing functions of two variables. In most such programs,  Traces in the vertical planes x = k and y =
{"Image DocumentName": "GRAPHS BY COMPUTERSComputer programs are readily available for graphing functions of two variables.", "Image ImageDescription": "In most such programs, Traces in the vertical planes x = k and y = k are drawn for equally spaced values of k. Parts of the graph are eliminated using hidden line removal.", "Image XResolution": "37", "Image YResolution": "37", "Image ResolutionUnit": "Pixels/Centimeter", "Image Software": "SlidePlayer", "Image YCbCrPositioning": "Centered"}