How to Graph Trig Functions on the TI-84 Plus
The TI-84 Plus graphing calculator has built-in features especially designed for graphing trigonometric functions. It produces graphs that look like graphs you see in text books; and when you trace these graphs, the x-coordinate of the tracing point is always given as a fractional multiple of
To use these features when graphing trigonometric functions, follow these steps:
Put the calculator in Function and Radian mode.
Press [MODE]. In the third line, highlight Radian, and in the fourth highlight Func. (To highlight an item in the Mode menu, use the
keys to place the cursor on the item, and then press [ENTER].)
Enter your trigonometric functions into the Y= editor.
Press [ZOOM] to graph the function.
[ZOOM] invokes the ZTrig command that graphs the function in a viewing window in which
It also sets the tick marks on the x-axis to multiples of
When you trace a function graphed in a ZTrig window, the x-coordinate of the trace cursor will be a multiple of
although the x-coordinate displayed at the bottom of the screen will be a decimal approximation of this value.
If you want to graph trigonometric functions in Degree mode, to get at least one period of a sine or cosine function, you must set Xmin to 0 and Xmax to
This is why it is a lot easier to graph trig functions in Radian mode. Setting the mode to degrees or radians is explained in Step 1.