Texas Instruments TI-86 Manual Book page 387

ZOut
† GRAPH ZOOM menu
ZPrev
† GRAPH ZOOM menu
ZOut
Zooms out to display more of the graph, centered
around the current cursor location.
Zoom factors are set by the values of built-in variables
xFact and yFact ; the default is 4 for both factors.
ZPrev
Replots the graph using the window variable values of
the graph that was displayed before you executed the
previous ZOOM instruction.
Chapter 20: A to Z Function and Instruction Reference
In
Func
y1=x sin x b
ZStd b
ZOut b
375
graphing mode:
Done