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.
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.
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.
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] .
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:
Using the ARROW keys, place the cursor on the desired Zoom In center. Below, the center was chosen as approximately (1.277,-3.226). An arrow, which is not part of the calculator display indicates the location of this point.
To determine this point to three decimal places, press ENTER repeatedly, recentering the cursor in between unless the first three decimal places stop changing. This is illustrated in the following diagrams.
Continuing in this manner, this minimum (lowest) point to 3 decimal places is approximately (1.291,-3.303).
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