To start the function graph tracing feature on the graphical calculator panel, click the trace button.
Function tracing feature which allows for graphically tracing each plotted data point for each function plotted on the graph.
The function tracing command include the following features:

• additional clicks on the trace button will put trace point at the beginning of each graph
• clicking the clear button will exit trace mode
• blue will be used for color of function trace point.
• coordinates will appear and change on function plotter window corresponding to the coordinate currently at the trace point.
• use arrow keys to move the trace point on the function graph while in trace mode
• PageUp/PageDown keys for moving whole number distances at a time while in trace mode
• the enter button will toggle between end points of function graph while in trace mode