Window Editor Variables in Sequence Mode on TI-83 Plus
The Window editor when the TI-83 Plus graphing calculator is in Sequence mode offers the following list of variables you must set when graphing a sequence:
nMin: This setting contains the first value of the independent variable n. It must be set equal to 0 or a positive integer.
nMin appears both in the Window editor and in the Y= editor. If you change the value of nMin in either the Window editor or the Y= editor, the value of nMin will automatically be updated in both editors.
nMax: This setting contains the largest value of the independent variable n that you want the calculator to use to evaluate your sequences. For example, if nMin = 0 and nMax = 100, the calculator will evaluate the first 101 terms in each sequence.
nMax must be set equal to a positive integer that is greater than nMin. Be reasonable when entering a value for nMax. If you’re graphing three sequences and nMax = 1,000, it’s going to take the calculator at least a minute to get the job done.
If it’s taking a long time for the calculator to graph your sequences, and you start to regret that rather large value you placed in nMax, press [ON] to terminate the graphing process. You can then go back to the Window editor and adjust the nMax setting.
PlotStart: This setting tells the calculator where you want to start graphing in each sequence. For example, if PlotStart = 20, then the calculator starts the graph with the 20th term in each sequence.
This isn’t always intuitive. If nMin = 1, then the 20th term in the sequence u(n) is u(20). But if nMin = 0, then the 20th term in this sequence is u(19).
PlotStart must be set equal to a positive integer. Usually it’s set equal to 1 so that the graph starts at the beginning of a sequence.
PlotStep: This setting tells the calculator if you want to skip graphing any terms in each sequence. A setting of 1 tells the calculator to graph every term in each sequence; a setting of 2 tells it to graph every other term; and a setting of 3 tells it to graph every third term, and so on.
PlotStep must be set equal to a positive integer. Usually it’s set equal to 1 so that the graph shows all terms in your sequences.
You use the remaining items in the Window editor to set a viewing window for the graph.