Graphing Calculator
Free interactive graphing calculator: plot up to three functions, pan, zoom, read coordinates, with a table of values. No signup.
How to use
Type each function using ^ for powers, x^2 means x², 2*x means 2x, and press Plot. Up to three functions draw in different colors with a legend. Drag the graph to pan, scroll (or use the buttons) to zoom, and hover or tap to read exact coordinates. Keyboard users: focus the graph and use arrow keys to pan, +/− to zoom.
Scope: polynomials, trigonometric (sin, cos, tan), exponential (exp), logarithmic (ln, log), roots (sqrt), and absolute value are supported. Intersections, roots, and derivative readouts are planned next.
Reading a graph
A graph turns algebra into shape. Where the curve crosses the x-axis, y = 0, those are the roots. Where it peaks or valleys, the derivative is zero, maxima and minima. A steep section means fast change; a flat one means slow. Plotting two functions together shows where they are equal: the intersection points satisfy f(x) = g(x).
Worked example
Example: where does y = x² − 4 cross the x-axis?
Step 1, Plot y = x^2 − 4. You see a U-shape crossing the x-axis twice.
Step 2, Read: hover near the crossings; the readout shows y = 0 at x = −2 and x = 2.
Step 3, Verify: (−2)² − 4 = 0 ✓ and 2² − 4 = 0 ✓. The graph suggested, algebra confirmed.
Common mistakes
- Wrong window: “nothing plotted” usually means the interesting part is outside the view, zoom out or reset before assuming the function is empty.
- Reading pixel crossings as exact: the graph shows approximate roots. Confirm with the quadratic calculator or algebra.
- Missing steep sections: near-vertical jumps between sample points can hide behavior. Zoom in to inspect suspicious regions.
Frequently asked questions
Type x^2. The caret means “to the power of”: x^3 is x cubed, 2*x is 2x. Spaces are ignored.
Usually the view window. The function may be plotted far outside −10…10, press Reset view, then zoom out. Also check the expression parsed without an error message under its box.
Visually, yes: plot both functions and hover where they cross, the readout shows the coordinates. Automatic intersection detection is planned for a later release.
Polynomials (x^2, 3x^3 − 2x), trig (sin(x), cos(x), tan(x)), exponentials (exp(x), e^x), logs (ln(x), log(x)), sqrt(x), cbrt(x), abs(x), plus constants pi and e. Implicit multiplication works: 2x means 2*x.