ZOOM 2:Zoom In

In order to see the effects of a ZOOM option, a graph must already be displayed on the screen.  To learn how to enter and graph a function, go to Graphing a Function . For example, the function = is graphed below.  

Screen Picture of TI-83 Calculator

The ZOOM 2:Zoom In option allows the user to select a new VIEWING RECTANGLE around a given point that is smaller than the existing VIEWING RECTANGLE.  Both the Zoom In and Zoom Out results depend on the ZOOM FACTORS.

To select the ZOOM 2:Zoom In option, first press the ZOOM key and then select 2. 

Screen Picture of TI-83 Calculator Screen Picture of TI-83 Calculator

Note: The X and Y coordinates may vary depending on what was last done on the calculator.  Regardless of what X and Y are displayed on the screen, they will remain in the center of the image.

Now press the ENTER key.  The VIEWING RECTANGLE will remain centered around the X and Y listed at the bottom of the screen, but the size of the VIEWING RECTANGLE will be 1/4 of its orginal size (assuming Xfact and Yfact are both 4).  Thus, the standard VIEWING RECTANGLE of [-10, 10, 1] X [-10,10,1] is now [-2.5,2.5,1] X [-2.5,2.5,1].  See the graph below.

Screen Picture of TI-83 Calculator

Pressing the ENTER key again gives a graph similar to the one shown below.  The new VIEWING RECTANGLE is [-0.625,0.626,1]  X [-0.625,0.626,1] . 

Screen Picture of TI-83 Calculator

The Zoom In option also may be centered on a point. As previously shown, first graph the function in the standard viewing rectangle (6:ZStandard ), press ZOOM, and then 2 to return to the following image:

Screen Picture of TI-83 Calculator

Using the ARROW keys, place the cursor on the desired Zoom In center.  Below, the center was chosen as approximately (1.287,-3.049).  An arrow, which is not part of the calculator display indicates the location of this point.  

Screen Picture of TI-83 Calculator

To zoom in leaving that point at the center, press ENTER repeatedly.

Screen Picture of TI-83 Calculator

Screen Picture of TI-83 Calculator  

 

   
 



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