How to Set the Mode on the TI83 Plus
The TI83 Plus Mode menu, which is accessed by pressing [MODE], is the most important menu on the calculator; it tells the calculator how you want numbers and graphs to be displayed.
One item in each row of this menu must be selected. Here are your choices:

Normal, Sci, or Eng:
This setting controls how numbers are displayed on the calculator. In Normal mode, the calculator displays numbers in the usual numeric fashion that you used in elementary school — provided it can display it using no more than ten digits. If the number requires more than ten digits, the calculator displays it using scientific notation.
In Scientific (Sci) mode, numbers are displayed using scientific notation; and in Engineering (Eng) mode, numbers are displayed in engineering notation. Here, the first answer is displayed in normal notation, the second in scientific notation, and the third in engineering notation.
In scientific and engineering notation, the calculator uses En to denote multiplication by 10^{n}.

Float 0123456789:
Select Float if you want the calculator to display as many digits as possible. Select 0 if you want all numbers rounded to an integer. If you’re dealing with money, select 2 so that all numbers will be rounded to two decimal places. Selecting 5 rounds all numbers to five decimal places, and, well, you get the idea.

Radian or Degree:
If you select Radian, all angles entered in the calculator are interpreted as being in radian measure; all angular answers given by the calculator will also be in radian measure. Similarly, if you select Degree, any angle you enter must be in degree measure, and any angular answer given by the calculator is also in degree measure.

Func, Par, Pol, or Seq:
This setting tells the calculator what type of functions you plan to graph. Select Func to graph plain old vanilla functions, y = f(x). Select Par to graph parametric equations; Pol to graph polar equations; and Seq to graph sequences. (Sequences are also called iterative equations.)

Connected or Dot:
In Dot mode, the calculator produces a graph by plotting only the points it calculates. In Connected mode, the calculator joins consecutively plotted points with a line.
Select the Connected mode because each of the graphing options (Func, Par, Pol, and Seq) allows you to select a graphing style, one of which is the dot style.

Sequential or Simul:
In Sequential mode, the calculator completes the graph of one function before it graphs the next function. In Simultaneous (Simul) mode, the calculator graphs all functions at the same time. It does so by plotting the values of all functions for one value of the independent variable, and then plotting the values of all functions for the next value of the independent variable.
Simul mode is useful if you want to see whether two functions intersect at the same value of the independent variable. You have to watch the functions as they are graphed in order to see if this happens.

Real, a + bi, or
If you’re dealing with only real numbers, select the Real mode. If you’re dealing with complex numbers, select a + bi if you want the complex numbers displayed in rectangular form. If you want complex numbers displayed in polar form, select the
mode.

Full, Horiz, or GT:
The Full screen mode displays the screen as you see it when you turn the calculator on. The other screen modes are splitscreen modes. The Horiz mode is for when you want to display a graph and the Y= editor or the Home screen at the same time. Use the GT mode when you want to display a graph and a table at the same time.
If you’re planning on graphing trigonometric functions, put the calculator in Radian mode. Reason: Most trig functions are graphed for
That is approximately
That’s not a bad value for the limits on the xaxis. But if you graph in Degree mode, you would need —
for the limits on the xaxis. This is doable . . . but it’s easier to graph in Radian mode.