##### TI-84 Plus CE Graphing Calculator For Dummies, 3rd Edition

The TI-84 Plus calculator has a variety of features that help you easily format the graph of a function. Set the graph format settings by following these steps:

1. Press [2nd][ZOOM] to access the Format menu.

See the first screen. Alternatively, access the Format menu from the Mode menu; press [MODE], and then highlight YES on the line that says, GO TO 2ND FORMAT GRAPH.

2. Set the format for the graph by using the

keys to place the cursor on the desired format, and then press [ENTER] to highlight it.

In the Format menu, each line of the menu will have one item highlighted. Keep in mind, the TI-84 Plus does not have as many options in the Format menu as the TI-84 Plus C does. An explanation of each menu selection follows:

• RectGC and PolarGC: This gives you a choice between having the coordinates of the location of the cursor displayed in (x, y) rectangular form or in polar form:

Select RectGC for rectangular form or PolarGC for polar form.

• GridOff, GridDot, and GridLine: If you select GridDot, grid points appear in the graph at the intersections of the tick marks on the x- and y-axes. See the second screen. If you select GridOff, no grid points appear in the graph. If you select GridLine, your graph background looks a lot like graph paper, as shown in the third screen.

• GridColor: If you place your cursor on GridColor, a menu spinner is activated. Use the

keys to choose one of 15 grid colors. The default color is light gray.

• Axes: If you place your cursor on Axes, a spinner is activated. Use the

keys to choose one of 15 Axes colors. Axes Off is also a choice in the spinner. See the first screen in the following figure. The default Axes color is black.

• LabelOff and LabelOn: If you want the x- and y-axes to be labeled, select LabelOn (as in the second screen). Because the location of the labels isn’t ideal, selecting LabelOff is usually a wise choice.

• CoordOn and CoordOff: This tells the calculator whether you want to see the coordinates of the cursor location displayed in the Graph border at the bottom of the screen as you move the cursor. Select CoordOn if you want to see these coordinates; select CoordOff if you don’t. See the third screen.

• ExprOn and ExprOff: If you select ExprOn, when you’re tracing the graph of a function, the definition of that function appears in the Graph border in the upper-left corner of the screen (see the third screen). If you select ExprOff and CoordOn, then only the number of the function appears when you trace the function. If you select ExprOff and CoordOff, then nothing at all appears on the screen to indicate which function you’re tracing.

• BorderColor: If you place your cursor on BorderColor, a spinner is activated. Use the

keys to choose one of four border colors. Why only four color choices? Many of the other colors would be too dark, making it difficult to read the expression and coordinate information in the Graph border. The four color choices are: 1-Light Gray (default), 2-Light Green, 3-Teal, and 4-White. See the first screen.

• Background: If you place your cursor on Background, a spinner is activated. Use the

keys to choose one of 15 colors that can serve as the background of your graph page. See the second screen. In addition to colors, you can use the spinner to choose one of 10 images. A preview of each image automatically pops up as you scroll through the spinner. See the third screen. The default background is set to Off.

• Detect Asymptotes: If you select Detect Asymptotes On, vertical asymptotes will not have any points graphed where the vertical asymptote is located as shown in the first screen.

Another way of thinking about this is your calculator is not trying to connect every point graphed to the next (across singularities). If you select Detect Asymptotes Off, the graph rate increases. This means there’s a strong likelihood that there will be a vertical line where the vertical asymptote is located as illustrated in the second screen.

Confused? Your calculator is trying to connect all the points that are graphed. So, if the limit of the function is positive and negative infinity on opposite sides of the vertical asymptote, a vertical line will appear because your calculator is trying to connect the points on each side of the vertical asymptote.