How to Zoom In and Out on the TI-84 Evo

On the TI-84 Evo's graph screen, press + to zoom in and − to zoom out. That works on OS 7.1 and later. On OS 7.0, use Zoom In and Zoom Out in the ZOOM menu instead.

Zoom in and out with + and −

Here's the graph of Y1 = X² − 4X + 3 in the window the calculator starts with. The bottom of this parabola is small and hard to read. (New to graphing? Graphing a function on the TI-84 Evo covers typing it in.)

The TI-84 Evo graph of Y1 equals X squared minus 4X plus 3 in the starting window, with the bottom of the parabola small near the origin
  1. Press +. The graph zooms in around the middle of the screen, so everything looks twice as big.
    The same parabola after one press of plus, twice as big and still centered on the origin
  2. Press + again. Now you can see where the curve dips below the x-axis and crosses back up.
    The parabola after a second press of plus, filling the screen and crossing the x-axis twice
  3. Press − twice. That's the subtract key. Each press zooms back out by the same amount, so two presses land on the view you started with.

On OS 7.0, + and − don't zoom: they leave the graph and type Ans+ on the home screen. Press clear, then graph to get back. Then press zoom, arrow down to Zoom In (or Zoom Out), and press enter. A cursor appears on the graph, and pressing enter again zooms around it.

Zoom in on one spot with Zoom Box

Zoom Box lets you draw a box around the part of the graph you want, and that part fills the screen.

  1. Press zoom. It's the middle key of the top row. The ZOOM menu opens with Zoom Box at the top.
    The TI-84 Evo ZOOM menu with 1:Zoom Box highlighted, and plus and minus shown beside Zoom In and Zoom Out
  2. Press enter. The status bar reads ZOOM BOX, and a small cursor appears in the middle of the graph.
    The graph with ZOOM BOX in the status bar and a cursor at X equals 0, Y equals 0
  3. Use the arrow keys to move the cursor to one corner of your box. Hold an arrow key to move faster. Here the corner goes just above and to the left of the bottom of the curve.
    The Zoom Box cursor moved to X equals 0.5, Y equals 0.5, above and left of the bottom of the parabola
  4. Press enter. That pins the first corner.
  5. Arrow to the opposite corner. The box stretches as the cursor moves.
    A small box drawn around the bottom of the parabola, from X equals 0.5 to 3.5
  6. Press enter. The graph redraws with only what was inside the box.
    The graph after Zoom Box: the bottom of the parabola fills the screen, crossing the x-axis near the top corners

The cursor and the ZOOM BOX label stay on the graph until you press clear.

Undo a zoom

Zoom Previous takes the graph back one zoom, whether that zoom came from the menu or the + key.

  1. Press zoom, then the right arrow. That opens the MEMORY tab, with Zoom Previous at the top (ZPrevious on OS 7.0).
    The MEMORY tab of the ZOOM menu with 1:Zoom Previous highlighted
  2. Press enter. The graph goes back to how it looked before the box.
    The parabola back in the starting window after Zoom Previous

The rest of the ZOOM menu

Each of these changes the window as soon as you select it. The names in parentheses are what OS 7.0 calls them.

  • Zoom Default (ZDecimal) puts the window back to the one the calculator starts with.
  • Zoom Square (ZSquare) makes one unit along x the same length on the screen as one unit along y, so a circle looks round. The starting window already has equal units, so you'll only see a change after a zoom like Zoom [−10,10].
  • Zoom [−10,10] (ZStandard) runs both axes from −10 to 10. Resetting the graphing window covers it.
  • Zoom Trig (ZTrig) sizes the window for sine and cosine graphs, as shown in graphing trig functions.
  • Zoom Fit (ZoomFit) keeps the left and right edges and moves the top and bottom until the part of the curve between those edges fits on the screen.
  • Zoom Stat (ZoomStat) fits the window around the points of a stat plot, as in plotting points.
  • Zoom Quadrant1 (ZQuadrant1) moves the axes to the bottom-left corner, so the screen shows mostly positive x and y.

Good to know

  • Zoom in around a spot you pick. Zoom In from the ZOOM menu puts a cursor on the graph. Move it to the spot with the arrows and press enter. Each extra enter zooms in again; clear stops.
  • Want exact edges? Adjusting the graphing window shows how to type them in yourself.