Plot a Function, See What It Actually Looks Like
Type in a function of x, hit graph, and it's plotted — the same Y= workflow as a TI-84 Plus CE. Enter your equation and get an interactive coordinate plane you can zoom, pan, and trace through.
It's useful for checking a homework answer, seeing what a function looks like before committing to an algebraic approach, and building a gut feel for how a coefficient or exponent bends a graph's shape — something that's genuinely easier to see than to imagine.
What You Can Graph
- Linear & polynomial functions: lines, parabolas, cubics, and higher-degree curves.
- Rational functions: including ones with vertical and horizontal asymptotes.
- Trigonometric functions: and their transformations (amplitude, period, phase shift).
- Exponential and logarithmic functions: graphed the same way as any other.
- Multiple functions plotted together: for comparing curves or finding intersections.
Reading the Graph
Once a function is plotted, trace along the curve to read off coordinate pairs, use zoom to focus on a specific region (helpful for locating roots or turning points precisely), and adjust the window manually if the automatic view doesn't capture the interesting part of the function.
Your First Graph, Step by Step
- Enter your equation in terms of x (e.g., y = 2x + 3, or x² − 4).
- Press graph to plot it on the coordinate plane.
- Use the zoom controls to adjust how much of the plane you can see.
- Trace along the curve to identify specific coordinate values.
Worked Example: Graphing y = x² − 4
Type x² − 4 into Y= and press GRAPH. You'll get an upward-opening parabola with its vertex at (0, −4). It crosses the x-axis at x = −2 and x = 2 — you can check this algebraically too, since x² − 4 factors as (x − 2)(x + 2), and setting each factor to zero gives those same two roots.
Trace along the curve to x = 1 and you should land on y = 1² − 4 = −3. If your traced value doesn't match a value you calculated by hand, it's usually a window or trace-position issue rather than a graphing error — double-check where the cursor actually sits on the x-axis before assuming the plot is wrong.
Frequently Asked Questions (FAQ)
Why isn't my graph showing up?
Almost always a window-range issue. If the interesting part of the function is off in the distance, widen the view manually.
Can I plot more than one equation?
Yes, enter several and they'll show up together — great for comparisons or intersections.
Radians or degrees for trig graphs?
Whichever you set the mode to — the same equation looks very different depending on which one you pick.
Is this free to use?
Yes, no account needed.
Can I zoom into a specific area?
Yes, useful for pinning down a root or turning point precisely.
What about rational functions with asymptotes?
Enter it like any other function — you'll see the curve approach the asymptote without crossing it.
Can I find where two graphs intersect?
Plot both together and use trace or the intersection tool to read the coordinates.
Does it work on mobile?
Yes, it works fine on phones and tablets, not just desktop.
What if I mistype my equation?
It'll flag it — usually a mismatched parenthesis or a missing multiplication sign.
Good for checking algebra homework?
Yes — plot it and see whether your answer (a root, a vertex) actually matches what the graph shows.