HP 50G

Page 12-34
of y(x,y) = constant, for the solution of y’ = f(x,y). Thus, slope fields are useful
tools for visualizing particularly difficult equations to solve.
Try also a slope field plot for the function y’ = f(x,y) = - (y/x)
2
, by using:
Θ Press „ô, simultaneously if in RPN mode, to access to the PLOT SETUP
window.
Θ Change
TYPE to Slopefield.
Θ Press ˜ and type ‘− (Y/X)^2’ @@@OK@@@.
Θ Press @ERASE @DRAW to draw the slope field plot. Press @EDIT L @LABEL
@MENU to see the plot unencumbered by the menu and with identifying labels.
Θ Press LL@)PICT to leave the EDIT environment.
Θ Press @CANCL to return to the PLOT WINDOW environment. Then, press
$ , or L@@@OK@@@, to return to normal calculator display.
Fast 3D plots
Fast 3D plots are used to visualize three-dimensional surfaces represented by
equations of the form z = f(x,y). For example, if you want to visualize z = f(x,y)
= x
2
+y
2
, we can use the following:
Θ Press „ô, simultaneously if in RPN mode, to access to the PLOT SETUP
window.
Θ Change
TYPE to Fast3D.
Θ Press ˜ and type ‘X^2+Y^2’ @@@OK@@@.
Θ Make sure that ‘X’ is selected as the
Indep: and ‘Y’ as the Depnd: variables.
Θ Press L@@@OK@@@ to return to normal calculator display.
Θ Press „ò, simultaneously if in RPN mode, to access the PLOT
WINDOW screen.
Θ Keep the default plot window ranges to read:
X-Left:-1, X-Right:1, Y-Near:-1, Y-
Far: 1, Z-Low: -1, Z-High: 1, Step Indep: 10, Depnd: 8