Texas Instruments TI-82 User Manual - Page 75

Exploring a Graph with the Free-Moving Cursor While a graph is displayed, you can move the free-moving cursor anywhere on the graph and display the coordinates of any location on the graph. Free-Moving Cursor You can use |, ~, }, or † to move the cursor around the graph. When you first display the graph, no cursor is visible. As soon as you press |, ~, }, or †, the cursor moves from the center of the viewing window. As you move the cursor around the graph, the coordinate values of the cursor location are displayed at the bottom of the screen (if CoordOn). Coordinate values generally appear in normal floating-decimal format. The numeric display settings on the MODE screen do not affect coordinate display. To see the graph without the cursor or coordinate values, press ' or Í. When you press |, ~, }, or †, the cursor moves from same position. Graphing Accuracy The free-moving cursor moves from dot to dot on the screen. When you move the cursor to a dot that appears to be "on" the function, it may be near, but not on, the function; therefore, the coordinate value displayed at the bottom of the screen is not necessarily a point on the function. To move the cursor along a function, use TRACE (page 3.14). The display coordinate values of the free-moving cursor approximate actual math coordinates accurate to within the width/height of the dot. As Xmin and Xmax (and Ymin and Ymax) get closer together (after a Zoom In, for example), graphing accuracy increases, and the coordinate values more closely approximate the math coordinates. ) Free-moving cursor "on" the curve Function Graphing 3-13