ZStandard, ZDecimal, and ZTrig Commands on the TI83 Plus
ZStandard, ZDecimal, and ZTrig Zoom commands on the TI83 Plus graphing calculator help you to initially graph or regraph your function in a preset viewing window.
To use these zoom commands, enter your function into the calculator, press [ZOOM], and then press the key for the number of the command. The graph automatically appears.

ZStandard: This command graphs your function in a preset viewing window where
and
You access it by pressing [ZOOM][6].
This is a nice Zoom command to use when you haven’t the slightest idea what size viewing window to use for your function. After graphing the function using ZStandard, you can, if necessary, use the Zoom In and Zoom Out commands to get a better idea of the nature of the graph.

ZDecimal: This command graphs your function in a preset viewing window where
and
It is accessed by pressing [ZOOM][4].
When you trace a function graphed in a ZDecimal window, the xcoordinate of the trace cursor will be a multiple of 0.1.

ZTrig: This command, which is most useful when graphing trigonometric functions, graphs your function in a preset viewing window where
and
It also sets the tick marks on the xaxis to multiples of
You access ZTrig by pressing [ZOOM][7].
When you trace a function graphed in a ZTrig window, the xcoordinate of the trace cursor will be a multiple of