Graphing

How to Display a Graph

To graph a function, constant, list of (x,y) data pairs, or a linear regression simply select one of these types of items in the stack and hit the "graph" button in the "general" menu. If no entry is selected the topmost entry on the stack will be graphed. After the graph page is exited, the graphed expression remains on the stack with a "graph" button below the expression. This is to make it easy to look at the graph again later if desired. When displaying a graph a second time, the calculator will remember any change made to graph settings for that graph.

Displaying a Graph within Chosen Limits

There is also the option to display a graph within a given set of limits, rather than changing the limits after initially displaying the graph by using the graph settings. This is accomplished by hitting the "graph" button with the following items on the stack:

    Element to graph, (xmin, xmax, ymin, ymax)

The xmin, xmax, etc. must be placed within parentheses as shown to be recognized as graphing limits.

Types of Graphs

The following items may be graphed:

Functions - Functions or formulas with only one variable may be graphed (that variable may be repeated multiple times in the function - e.g. "sin(x) + x"). See the help section on names, labels and functions for more information on entering functions.

Constant Values - For convenience it is possible to graph a constant value, which can be any ordinary expression not containing a variable. This will display as a horizontal line representing a given y-value. This is handy when graphing lists to see where another graph hits a particular value.

(x,y) Data Pairs - A list of (x,y) data pairs may be graphed to visually check if there is a relation between the x and y values. See the help section on statistics for more information on entering (x,y) data.

Linear Regressions - If a Linear Regression is performed on a list of points ("LinRegr" in the statistics menu) and then the "LinRegr" stack entry is graphed, the graph will contain the original list of points and the best fit line.

Lists of Items - Multiple items may be shown on the same graph by placing any of the above items within a list and then selecting the list before hitting the "graph" button.

Display of Critical Points

Function graphs will display markers at critical points such as roots, local minimums, local maximums, and points where graphs intersect. Mousing over these markers (or pressing and holding them on a touch screen) will display the type of critical point and the exact coordinates of the point. Display of critical points may be turned on or off using the settings icon (reached by clicking the gear icon on the right side of the graph).

Adjusting The Graph Scale and Range

The scale of the graph may be adjusted by either zooming in and out or by changing the Xmin, Xmax, Ymin, Ymax values in the settings menu (reached by clicking the gear icon on the right side of the graph). Zooming in and out may be accomplished by using a "pinch" gesture (on a touch screen), by using the mouse wheel in combination with the "control" key on the keyboard, or by clicking on the +/- magnifying glasses on the side of the graph.

The range of values displayed may be adjusted by dragging the graph or by using the scrollbars on the bottom and right sides of the graph or by using the mouse wheel to scroll up and down.

Clicking on the Graph

Touching or clicking on the graph will cause the coordinates of the point on the graph to be displayed. If the selected point is near a critical point, the coordinates will be displayed for that critical point along with a description of the point (local maximum, root, etc.).