Graphing Calculator
Plot any function of x on an interactive graph - drag to pan, scroll to zoom, add up to 5 functions in different colors, and read values straight off the curve.
Plot it
Type a function of x, e.g. \(x^2\), \(\sin(x)\), \(2x+1\). Drag to pan, scroll or pinch to zoom.
Table of values (f1)
| x | f(x) |
|---|---|
| -2 | 4.0000 |
| -1 | 1.0000 |
| 0 | 0.0000 |
| 1 | 1.0000 |
| 2 | 4.0000 |
Reading a Graph
A graph turns algebra into a picture. Where the curve crosses the x-axis, \(f(x) = 0\) — those are the roots (solutions). Where two curves cross each other, both functions agree — that's the solution to \(f(x) = g(x)\). The steepness shows how fast the function changes: flat stretches mean slow change, steep stretches mean fast change.
Zooming and Panning
Start with the default view (x from −10 to 10). Drag to move around, scroll or pinch to zoom. Zooming in on a crossing shows the root more precisely; zooming out reveals the big picture — for example, that \(x^2\) keeps growing while \(\sin(x)\) just keeps waving. Use "Reset view" any time you're lost.
Common Functions to Try
Lines: \(2x+1\). Parabolas: \(x^2\), \(-x^2+4\). Waves: \(\sin(x)\), \(\cos(2x)\). Growth: \(2^x\), \(e^x\) (type it as e^x). Roots: \(\sqrt{x}\) — defined only for x ≥ 0, so half the graph is empty, which is itself the lesson. Plot \(x^2\) and \(2x+1\) together and find where they meet.
My saved numbers reuse them in any calculator
Save a number once — like your rent or hourly rate — then just type its name instead of the number, in any calculator here. You can also type formulas like 5000 * 1.1 right into any box.
Saved only in this browser — nothing is sent to us.
Frequently Asked Questions
How do you graph a function?
Type the function with x as the variable - for example x^2 - and it plots immediately. Where the curve crosses the x-axis, f(x) = 0: those are the roots. Where two curves cross, the functions are equal there.
What functions can I type?
Anything math.js understands: x^2, sin(x), cos(2*x), sqrt(x), 2^x, abs(x), and combinations like x^3-2*x+1. Use ^ for powers and * for multiplication.
How do I find where a function equals zero?
Look for x-axis crossings on the graph, then use the root finder: enter an x guess near the crossing and it pinpoints the root with bisection.
Why is part of my sqrt(x) graph missing?
Square roots of negative numbers are not real, so sqrt(x) has no graph left of x = 0. The empty half is the lesson: the function is only defined for x >= 0.
Can I compare two functions?
Yes - click "+ Add function" (up to 5). Each gets its own color, and the intersection tool lists every point where the first two cross within the current view.