Graphing Calculator
Plot functions on an interactive graph — free online graphing calculator, no sign-up.
y = f(x), e.g. x^2-3, sin(x), 2*x+1
About this calculator
A graphing calculator draws the graph of one or more functions of x. Enter equations like y = x^2 - 3 or sin(x), and the calculator plots them on an interactive grid you can zoom and pan. Add several functions at once to compare them, each in its own colour.
It evaluates each function at many x-values across the visible window and joins the points into a smooth curve, redrawing as you scroll to zoom or drag to pan so the axes and grid always rescale to what you are looking at. Any expression the scientific calculator understands works here — polynomials, trigonometry, logarithms, exponentials, roots and combinations — and each function you add is drawn in a distinct colour so several curves can be compared on one grid.
For a worked example, plotting y = x^2 - 3 gives an upward parabola whose lowest point sits at (0, -3) and which crosses the x-axis near x = -1.73 and x = 1.73 (where x^2 = 3). Add y = x - 1 on the same grid and the two curves meet where a line crosses the parabola, giving a visual solution to x^2 - 3 = x - 1. It is used to explore the shape of a function, find roots and intercepts, spot maxima and minima, and see where two graphs intersect.
Frequently asked questions
How do I enter a function?
Type an expression in x, such as x^2, sin(x) or 2*x+1, into the graphing calculator. You can add multiple functions and each is drawn in a different colour.
Can I zoom and pan?
Yes. Scroll or use the zoom buttons to zoom, and drag the graph to pan around. The axes and grid rescale automatically.
What functions can I plot?
Any expression the scientific calculator supports — polynomials, trig, logs, exponentials, roots and combinations of them.
How do I plot two functions to find where they intersect?
Enter each function on its own line, for example y = x^2 - 3 and y = x - 1. Both curves are drawn on the same grid, and the points where they cross are the solutions to the two expressions being equal.
How do I graph a parabola like y = x^2 - 3?
Type x^2 - 3 as the function. The result is a U-shaped parabola with its vertex at (0, -3); zoom out or pan to see where it crosses the x-axis near ±1.73.
Can I plot trigonometric functions?
Yes. Enter sin(x), cos(x) or tan(x) and the wave is drawn across the window. Combine them with other terms, such as sin(x) + x/2, to see the combined shape.
Why does my graph look empty or flat?
The curve may lie outside the current view. Zoom out or pan until it comes into range — for steep or large-valued functions you often need to zoom out on the y-axis to see the whole shape.
Results are estimates for general guidance only, not financial, medical or tax advice.