You select a program or equation to be plotted as follows:
1. To select an equation from the EQN list: Press EQN to enter equation mode; use the up/down arrows to find the equation you want to plot; press PLOT.
2. To select an equation that is stored in a variable: press PLOT to enter the plotting menu; press EQN (this is the EQNPLOT function); select the variable containing the equation.
3. To select program: press PLOT to enter the plotting menu; press PGM (this is the PGMPLOT function); select the program.
The equation or program you select for plotting will replace the previous one. Note that there is no option to remove the current plot equation or program without selecting a new one.