The TI-84 Plus C graphing calculator not only helps you make graphs, but its Zoom commands also help you highlight specific areas of a graph, redraw graphs in certain ratios, and otherwise tweak graphs to suit your needs. The following list shows you what each Zoom command does:

• ZBox: Draws a box around a portion of the graph and redraws the graph in a viewing window that has the dimensions of the box.

• Zoom In: Zooms in on the graph at the location of the cursor.

• Zoom Out: Zooms out on the graph at the location of the cursor.

• ZDecimal: Draws the graph in a –6.6 ≤ x ≤ 6.6 and –4.1 ≤ y ≤ 4.1 window. When the graph is traced, the x-coordinate of the Trace cursor equals an integral multiple of 0.1.

• ZSquare: Redraws the graph in a window that makes circles look like circles instead of ellipses.

• ZStandard: Draws the graph in a –10 ≤ x ≤ 10, –10 ≤ y ≤ 10 window.

• ZTrig: Draws the graph in a –11π/4 ≤ x ≤ 11π/4 and –4 ≤ y ≤ 4 window. When the graph is traced, the x-coordinate of the Trace cursor equals an integral multiple of π/24.

• ZInteger: Redraws the graph so that when it is traced, the x-coordinate of the Trace cursor equals an integer.

• ZoomStat: Finds an appropriate viewing window for stat plots.

• ZoomFit: Finds an appropriate viewing window for graphing functions, parametric equations, polar equations, or sequences.

• ZQuadrant1: This command graphs your function in a preset viewing window where 0 ≤ x ≤ 13.2 and 0 ≤ y ≤ 13.2. When you trace a function graphed in this window, the x-coordinate of the Trace cursor will be a multiple of 0.1.

• ZFrac1/2: This command graphs your function in a preset viewing window where –66/2 ≤ x ≤ 66/2 and –41/2 ≤ y ≤ 41/2. When you trace a function graphed in this window, the x-coordinate of the Trace cursor will be a multiple of 1/2.

• ZFrac1/3, ZFrac 1/4, ZFrac1/5, ZFrac 1/8, ZFrac1/10: These commands graph your function in a preset viewing window and work in the same manner as ZFrac1/2 does. If you think of d as the denominator of your fraction, then the viewing window is –66/dx ≤ 66/d and –41/dy ≤ 41/d. Tracing with these commands let you trace the x-coordinates by multiples of 1/d.