Graphing Calculator - Plot Functions, Find Roots & Intersections Online
Graphing Calculator
Plot up to three functions, then pan, zoom and read off roots
Three Functions at Once
Each curve has its own colour and line style (solid, dashed, dotted), so they stay distinguishable in print and for colour-blind readers.
Roots and Intersections
Roots are found by bisection on every sign change, plus a separate search for roots that only touch the axis, such as x^2 at 0.
Pan and Zoom
Drag the graph to move around and use the wheel or the buttons to zoom. The roots and the table update to the new window.
Private and Offline-Friendly
Everything is calculated in your browser. Nothing you type is sent anywhere.
How to Type Functions
Write functions the way you would on paper, using x as the variable: x^2 - 4, 2x + 1, sin(x)/x, sqrt(x), exp(-x^2), abs(x). Multiplication can be implied (3x), ^ means a power, and pi and e are the usual constants. Both ln(x) and log(x) are the natural logarithm; use log10(x) for base 10. Angles in trigonometric functions are in radians.
Where a function is undefined, such as sqrt(x) for negative x or 1/x at 0, the curve simply stops, and a sign change across a vertical asymptote is not reported as a root. Roots and intersections are found numerically inside the current window and shown to six decimal places, so zoom out if you expect one that is not listed.
Key Takeaways
- Natural notation: Implied multiplication, powers with ^, and "y =" or "f(x) =" prefixes all work.
- Honest gaps: Asymptotes and undefined regions are left blank instead of being joined by a false line.
- Table of values: Eleven evenly spaced points across the window give you exact numbers to check against.