TI-92 Help -- Making a Table of Values for a Sequence

Now use the cursor pad to select the SEQUENCE option. Then press ENTER to set this option. Then press ENTER again to save the new option.

NOTE: The Graph MODE must be set to SEQUENCE before setting the WINDOW settings as described below.

The WINDOW options should be set as if you were going to graph the sequence or sequences. In fact, usually tables and graphs are used together to study sequences.

Press Green-diamond WINDOW to get to the WINDOW menu shown at the right.

This screen allows you to set the following items.

• nmin -- the smallest value for n. This must be an integer >= 0. It designates the index of the first term in the sequence to be computed. It is usually 1 or 0.

• nmax -- the largest value for n. This must be a positive integer >= nmin. It designates the index of the last term in the sequence to be computed.

• plotstrt -- this indicates the first term to be plotted. Notice that the terms plotted may be different from the range of terms computed -- for example, if nmin = 1 and plotstrt = 11 the first ten terms will be computed but not plotted.

• plotstep -- the increment used for determining which terms are plotted. Notice that if plotstep = 2 every other term will be plotted although all the terms will be computed.

• xmin -- the low end of the x-axis range.

• xmax -- the high end of the x-axis range.

• xscl -- the distance between x-axis tick marks.

• ymin -- the low end of the y-axis range.

• ymax -- the high end of the y-axis range.

• yscl -- the distance between y-axis tick marks.

• xres -- the pixel resolution. Usually this is set at 2 and the calculator computes the values of the function at every other pixel along the x-axis and fills in linearly. Higher numbers produce faster but rougher graphs. When xres is set at 1, functions are evaluated at every pixel along the x-axis.

For sequences tblStart is usually 0 or 1 and delta-table is 1.

If tblStart is greater than nmin in the WINDOW menu then the table will begin with tblStart even though the sequence is computed from nmin.

Graph <-> should be set to OFF and Independent should be set to AUTO .

You may use this screen to describe one or more sequences. The sequences are called u1, u2, and so forth. Each sequence is described by a pair of lines as shown in the screen above. The first line -- something like --

is called the change equation and describes how the sequence changes from one term to the next. Notice that the right hand side describes how to compute each term u1(n) in terms of the preceding term u1(n - 1).

The second line describes the initial value of the sequence -- that is, the value of the first term.