Texas Instruments TI-73 Manual Book page 10

Tracing the Vector History
You can trace the vector history just as you would trace a
function graph on the TI-73.
Press ) to enter Trace mode. You see two cursors: a vector
cursor and a corresponding number line cursor. As both cursors
move simultaneously, the exact corresponding x-value is
displayed at the bottom left corner of the screen. The entry line
only displays the expression without its numerical result.
The cursor traces in increments according to the value set
Scale
on the screen. For more information on
WINDOW WINDOW
values, see the section entitled, Adjusting the Number Line
Window Values.
Number Line/Fraction Line for the TI-73 Page 10