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Graphing Basic Trig Functions
(This page concentrates on graphing in Radian mode.)
 

Graph y = sin(x)

       Enter the function.              Set the MODE to Radian.              Choose ZOOM #7 ZTrig
  1     2       3
Choosing ZOOM #7 ZTrig will set the x interval from 4,
set the y interval from -4 < y < 4, and set the increment at 5.
Depending upon your desired graph, you may wish to further adjust these values under WINDOW.
7

NOTE:  If you do a ZOOM #7 ZTrig while in DEGREE mode, the x interval will be set from -352.5º to 352.5º, with the y interval from -4 to 4, and the increment set at 90º.

 

Graph y = tan(x)

Enter the function.              Set the MODE to Radian.            Choose ZOOM #7 ZTrig
8     9       10
 

cat

A Problem with Older Calculators:

"Wow!  Look! 
It even graphed the asymptotes!!"

N O T !!!!!!!

11
These vertical lines were not the asymptotes.  They were simply the calculator behaving as it should in "Connected" mode -- it was "connecting" the points.

 

Here was the graph in DOT mode.  No asymptotes!!

 12
NOTE:  Starting with the TI-84+ Operating System V 2.40,
this problem of "not actual asymptotes appearing" no longer exists.

 
Graph  y = 2sin(3(x - 2)) + 12

This is a sinusoidal equation of the form y = Asin(B(x - C)) + D, where A is the amplitude, B is the frequency, C is the horizontal shift and D is the vertical shift.    The period of this graph will be 13. 

When graphing such equations, it may be necessary to adjust the window to "see" the graph.  If ZOOM #7 Trig is used with this graph, the screen will appear empty.  The vertical shift tells you that the graph has been "raised" by 12 units.  Adjust the yMax and yMin accordingly.  The yMin has been set to 0 for this example to establish a reference point when viewing the graph.

Enter the function.                  Set the MODE to Radian.           Adjust the ZOOM #7 ZTrig
14     15     16
Graph
17
Adjust the WINDOW further for additional examinations of the graph.

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