How to Graph on a TI-84: Your Complete, Step-by-Step Visual Guide

Graphing functions is the most powerful feature of your TI-84 calculator, turning complex equations into clear, visual graphs. Whether you’re using a physical TI-84 Plus or a free online emulator like TI84.online, the process is the same. This human-written guide will walk you through it, with pro tips to avoid common mistakes.

Step-by-Step: How to Graph Any Function

Follow these steps to graph everything from simple lines to complex polynomials.

Step 1: Access the Y= Editor

Press the Y= button (top-left of the keypad). You’ll see a list, usually Y1, Y2, etc. This is where you type your equations.

Pro Tip: You can graph up to 10 equations at once to compare them.

Step 2: Enter Your Equation

Using the keypad, type your equation next to an empty Y= slot.

For y = 2x + 5, type: 2 X,T,θ,n + 5
For y = x², type: X,T,θ,n x²
Use the (-) key for negative numbers, not the subtraction key.

Step 3: Set Your Viewing Window (The “GRAPH” Key)

Press the GRAPH button. If you don’t see your graph or it looks off, you need to adjust the window.

Press the WINDOW button to set the graph’s boundaries.
- Xmin / Xmax: The left and right edges of the screen (e.g., -10 to 10).
- Ymin / Ymax: The bottom and top edges of the screen (e.g., -10 to 10).

Step 4: Adjust and Analyze

ZOOM: Press this for quick presets. ZoomFit (Option 0) automatically fits your Y-values.
TRACE: Press this, then use the left/right arrows to move along the curve and see exact (X,Y) coordinates.
Find Specific Points: Press 2nd then TRACE (CALC) for tools like zero (x-intercept), minimum, or maximum.

Visual Example: Graphing y = x² – 4

Here’s how this common parabola would look graphed on a TI-84 interface. Notice the key points at (-2,0), (0,-4), and (2,0), which you can find using the CALC menu.
(A visual representation of the graph and keypad would be placed here.)

✅ Pro Tips & Common Mistakes to Avoid

“Invalid Dim” Error: This usually means your STAT PLOT is on. Press 2nd Y= (STAT PLOTS), select the plot, and choose Off.
Graph is Too Small or Off-Screen: Use WINDOW to manually adjust ranges or use ZOOM ZoomFit.
Graph Looks Chunky or Jagged: Your Xres setting in the WINDOW menu might be too high (it controls resolution). Set it to 1 for the smoothest graph.
Forgetting to Clear Old Equations: Always check the Y= editor for leftover equations from previous work that might clutter your new graph.

Graphing on a Physical TI-84 vs. Online Emulator

Feature	Physical TI-84 Plus	TI84.online Free Emulator
Cost	$100+	Completely Free
Access	Must have device	Any browser, any device
Graphing Steps	Identical to steps above	Identical to steps above
Best For	Exams, classrooms where phones/computers aren’t allowed	Homework, practice, study sessions, quick access
Trial Function	Not possible without resetting	Easy to experiment without fear of losing work

(FAQ)

Absolutely Websites like TI84.online provide a full, free emulator that works exactly like a physical calculator in your web browser. Just click the Y=button on the virtual keypad and start typing no downloads or cost.

The top three culprits are:

1. STAT PLOTS are turned on (go to 2ndY=to turn them off).

2. your WINDOWsettings are inappropriate for the equation.

3. there’s a syntax error in your Y=equation (check for missing parentheses).

You use logical conditions.

For example,

to graph y = x² for x < 0 and y = x+2 for x ≥ 0, you would enter:
Y1= (X^2)/(X<0)
Y2= (X+2)/(X≥0)
The division symbol acts as a “where” condition for the calculator.

On a physical calculator, you need a special USB cable and software. With an online emulator like TI84.online, you can simply take a screenshot of your browser window—a much faster way to share your graph with a teacher or study group.

Ready to Practice Graphing?

The best way to learn is by doing. Try these steps right now on our free, full-featured TI-84 Online Calculator. It’s the perfect risk-free way to practice before a test or tackle your homework.