Texas Instruments TI-92 Owners Manual - Page 134

Tracing a Function To display the exact coordinates of any plotted point on a graphed function, use the ... Trace tool. Unlike the freemoving cursor, the trace cursor moves only along a function's plotted points. Beginning a Trace Note: If any stat plots are graphed (Chapter 16), the trace cursor appears on the lowest-numbered stat plot. From the Graph screen, press .... The trace cursor appears on the function, at the middle x value on the screen. The cursor's coordinates are displayed at the bottom of the screen. If multiple functions are graphed, the trace cursor appears on the lowest-numbered function selected in the Y= Editor. The function number is shown in the upper right part of the screen. Moving along a Function Note: If you enter an x value, it must be between xmin and xmax. To move the trace cursor: To the previous or next plotted point Do this: Press A or B. Approximately 5 plotted points Press 2 A or 2 B. (it may be more or less than 5, depending on the xres Window variable) To a specified x value on the function Type the x value and press ¸. The trace cursor moves only from plotted point to plotted point along the function, not from pixel to pixel. Tip: If your screen does not show coordinates, set the graph format so that Coordinates = RECT or POLAR. Press: TI.89: ¥ Í TI.92 Plus: ¥ F Function number being traced. For example: y3(x). Tip: Use QuickCenter, described on the next page, to trace a function that goes above or below the window. Trace coordinates are those of the function, not the pixel. Each displayed y value is calculated from the x value; that is, y=yn(x). If the function is undefined at an x value, the y value is blank. You can continue to trace a function that goes above or below the viewing window. You cannot see the cursor as it moves in that "off the screen" area, but the displayed coordinate values show its correct coordinates. Chapter 6: Basic Function Graphing 117