Evaluate a Function/ Value

We illustrate by evaluating Y1 = x^2 - x - 6 at x = 1.7.

A function may be evaluated from the graph screen. Press MENU 3 to access the GRPH-TBL screen. Enter the function into the equation editor, then press F5 to select DRAW. Adjust the graph view from either the zoom menu or by adjusting the View Window settings. The graph of the function in the standard window is shown at right.

From the graph screen, press F1 to select TRACE. Simply type in the input value; here,

1 . 7 EXE

The calculator then marks the point on the graph and displays the coordinates at the bottom of the screen. Press ESC to return to the graph menu.

Warning The typed value of x must be between the Xmin and Xmax values entered in the View Window; otherwise, an ERROR message appears. In that case, either adjust the window or evaluate the function from the table screen.

If you have multiple graphs appearing on the same screen, you can transfer from one graph to another using the thumb pad arrow keys. Accordingly, you may evaluate any function appearing in the graph window.

To obtain a functional value for an x-value not appearing in the window, press F5 to select TABL. Then press F1 to select EDIT. Enter your x-value of interest. The resulting values are then placed as the first items in the table.