Functions
Common functions (click to plot)
Parameters
Analysis
Scroll to zoom, drag to pan, hover to read coordinates

Why use this online function graph generator?

One-click common functions

Twelve built-in presets cover linear, quadratic, reciprocal, trigonometric, exponential and logarithmic functions — click one to plot it instantly, and overlay up to six curves with individual visibility.

Wheel zoom and drag panning

Zoom in on the cursor position and drag to move the viewport. Axis ticks and grid lines are recalculated automatically, so inspecting local detail is effortless.

Live parameter sliders

Three built-in sliders for a, b and c let you watch a family of curves such as y=a·sin(b·x) change in real time, making parameter effects intuitive.

Zeros, intersections and extrema

The tool automatically finds every zero, the intersection points between functions, and local maxima and minima, listing them in the analysis panel.

Derivatives and tangent lines

Enter x₀ to see each function's value and derivative at that point, and draw the tangent line to build intuition about instantaneous rate of change.

Export PNG and SVG

PNG is exported at high resolution, while SVG is a vector format that scales without loss, ready for papers, slides and print.

How to plot a function in four steps

1

Enter a function expression

Type y=f(x) into a function box, for example sin(x) or x^2/4-1. Implicit multiplication such as 2x and 3sin(x) works too, or click a "Common functions" button above to plot sine, exponential, logarithm and more in one click.

2

Adjust the view

Scroll the wheel to zoom and drag the mouse to pan, or click "Reset view" to return to the default range. Grid and labels can be toggled at any time.

3

Drag the parameter sliders

If the expression contains a, b or c, drag the sliders on the right to reshape the curve instantly, a great way to explore how parameters affect a graph.

4

Analyse and export

The analysis panel lists zeros, intersections and extrema. Enter x₀ to inspect derivatives and the tangent line, then click "Export PNG" or "Export SVG" to save.

Common use cases

Homework and study

Sketch the graph from a problem, check zeros and extrema, and verify conclusions quickly

Teaching slides

Drop a vector SVG into slides so it stays sharp at any size while explaining function behaviour

Papers and reports

Export clean high-resolution figures for model curves, error functions and fitting results

Engineering and analysis

Inspect transfer functions, decay curves and response functions at a glance

Building intuition

Drag the parameter sliders to connect "parameter" with "shape" in a hands-on way

Content and outreach

Produce clean, readable function figures for maths articles, videos and blogs

Function graphs explained

What is a function graph?

A function graph is the curve formed by all points (x, y) that satisfy y=f(x) in the Cartesian plane. It turns an abstract relationship into a shape you can see, letting you read off increasing and decreasing behaviour, zeros, extrema and symmetry at a glance. It is one of the most effective ways to study functions.

Why do trigonometric functions use radians?

This tool follows maths textbooks and programming languages and uses radians, defined as the ratio of arc length to radius. 180° equals π radians, so sin(pi/2)=1 and cos(pi)=-1. To enter an angle in degrees, convert first: 30° = pi/6 ≈ 0.5236 and 45° = pi/4 ≈ 0.7854.

How are zeros, intersections and extrema computed?

The tool samples the visible range densely. When two neighbouring samples have opposite signs the curve has crossed the axis, and the bisection method then halves the interval repeatedly to converge on the true zero. Subtracting one function from another and finding zeros gives the intersection points, while extrema are located where the numerical derivative (a central difference) changes sign. Results are numerical approximations shown to 4 significant digits.

Why export SVG as well as PNG?

PNG is a raster format and becomes jagged when scaled up. SVG is vector-based, describing the image with lines and text, so it stays perfectly sharp at any size, takes little space, and can be placed directly into Word, PowerPoint or LaTeX. Use PNG for bitmaps such as chat messages, and SVG for print or large displays.

Expression syntax cheat sheet

Category Syntax Notes and examples
Basic operators + - * / ^ % Add, subtract, multiply, divide, power, remainder, e.g. 2^10, 7%3
Parentheses ( ) Group expressions, e.g. (x+1)*(x-2)
Implicit multiplication 2x / 3sin(x) The multiply sign may be omitted between a number and a variable or function
Constants pi / e π ≈ 3.14159 and Euler's number e ≈ 2.71828
Variable and parameters x / a b c x is the independent variable; a, b and c are driven by the sliders
Trigonometric sin cos tan Radians; inverses are asin acos atan
Hyperbolic sinh cosh tanh Inverses are asinh acosh atanh
Exponential and log exp ln log log2 ln is natural log, log(x) is base 10, log(x,b) is base b
Other common sqrt cbrt abs sign Square root, cube root, absolute value, sign function
Rounding and aggregation floor ceil round min max For example max(sin(x), 0.5) takes the larger of the two

Frequently asked questions

Q: Is the function graph generator free?
A: Yes, it is completely free with no sign-up and no usage limits. All plotting and analysis run locally in your browser.
Q: Which functions and operators are supported?
A: Operators +, -, *, /, ^ (power), % and parentheses; functions sin, cos, tan, asin, acos, atan, sinh, cosh, tanh, exp, ln, log, log2, sqrt, cbrt, abs, sign, floor, ceil, round, min, max, pow, hypot and mod; constants pi and e; the variable is x and the parameters are a, b and c. Implicit multiplication such as 2x or 3sin(x) is also supported.
Q: Do trigonometric functions use degrees or radians?
A: They use radians, matching maths textbooks and programming languages. For example sin(pi/2) = 1. To enter 30 degrees, write sin(pi/6).
Q: How do I zoom or move the graph?
A: Scroll the mouse wheel over the canvas to zoom in and out (centred on the cursor), and hold the left mouse button to drag and pan. You can also use the zoom in, zoom out and reset view buttons at the top.
Q: How are zeros, intersections and extrema calculated?
A: The tool samples the visible range densely, detects where the function value changes sign, and then refines the position with the bisection method to find zeros and intersections. Extrema are located where the numerical derivative changes sign. Results are numerical approximations shown to 4 significant digits.
Q: How are derivatives and tangent lines shown?
A: Enter x₀ in the analysis panel and the tool computes each function's derivative at x₀ using central differences. Tick "Show tangent line" to draw the tangent at that point, marked with a filled circle.
Q: Can I use the exported images in papers and slides?
A: Yes. PNG is exported at high resolution with crisp edges, while SVG is a vector format that scales losslessly and can be edited in a text editor, which makes it ideal for papers, slides and printing.