What can this graphing calculator do?

You can plot up to 3 functions at once, set the x and y viewing window, and sample enough points to get smooth curves. It supports common functions like sin, cos, tan, log, ln, sqrt, abs, and combinations.

Change the X min, X max, Y min, and Y max values and click Plot again. This updates the viewport just like a handheld graphing calculator.

What syntax should I use?

Use standard math.js syntax: x^2, sin(x), cos(x), tan(x), log(x,10), ln(x)=log(x), sqrt(x), abs(x). Use * for multiplication, e.g. 2*x not 2x.

Does it find intersections or roots?

This tool focuses on plotting and inspection. You can visually locate intersections and then evaluate the functions at nearby x-values to refine the point.

Graphing Calculator

Free online graphing calculator. Plot up to 3 functions, set x/y range, sample points, and inspect values. Supports sin, cos, tan, exp, log, piecewise and compositions. Ideal for algebra, precalculus and calculus.

Full original guide (expanded)

Graphing Calculator

Plot functions in real time. Type your equations, set the window, and click Plot. You can add up to 3 functions to compare shapes, intersections, and behavior.

Functions f(x)

f₁(x) primary

f₂(x)

f₃(x)

Syntax: use * for multiply (2*x), pi, e, abs(), sqrt(), log(x,10), etc.

Window (view)

X min

X max

Y min

Y max

Samples (resolution)

Graph

If a function is undefined for part of the range (e.g. sqrt of negative), that segment is skipped.

How the graphing calculator works

To plot a function, we:

Take your x-range (for example −10 to 10).
Sample N points (default 300) evenly spaced across that range.
Evaluate each function at those x values using a math parser.
Feed the resulting x–y pairs into a charting engine to draw the curves.

If a function returns NaN or Infinity for some x, we drop that point, producing gaps for asymptotes.

Common functions to try

Linear: 2*x + 3

Quadratic: x^2 - 4*x + 2

Trigonometric: sin(x), cos(x), sin(x)/x

Exponential / log: exp(0.3*x), log(x,10)

Absolute value: abs(x)

Piecewise (basic): use if(x < 0, -x, x) kind of structures (math.js style).

FAQs

Can I plot parametric or polar?

This version focuses on Cartesian y = f(x). For parametric/polar you’d need a specialized plotter, but you can often rewrite simple cases as y = f(x).

Why is my graph cut off?

Your y-values may be outside the current view. Increase Y min/Y max and plot again.

Does it work on mobile?

Yes, it’s responsive and lightweight, unlike some desktop graphers.

Audit: Complete

Formula (LaTeX) + variables + units

This section shows the formulas used by the calculator engine, plus variable definitions and units.

Formula (extracted LaTeX)

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Formula (extracted text)

Linear: 2*x + 3 Quadratic: x^2 - 4*x + 2 Trigonometric: sin(x), cos(x), sin(x)/x Exponential / log: exp(0.3*x), log(x,10) Absolute value: abs(x) Piecewise (basic): use if(x < 0, -x, x) kind of structures (math.js style).

Variables and units

T = property tax (annual or monthly depending on input) (currency)

Sources (authoritative):

NIST — Weights and measures — nist.gov · Accessed 2026-01-19
https://www.nist.gov/pml/weights-and-measures
FTC — Consumer advice — consumer.ftc.gov · Accessed 2026-01-19
https://consumer.ftc.gov/

Changelog

Version: 0.1.0-draft
Last code update: 2026-01-19

0.1.0-draft · 2026-01-19

Initial audit spec draft generated from HTML extraction (review required).
Verify formulas match the calculator engine and convert any text-only formulas to LaTeX.
Confirm sources are authoritative and relevant to the calculator methodology.

Verified by Ugo Candido on 2026-01-19
Profile · LinkedIn

Formulas

(Formulas preserved from original page content, if present.)

Version 0.1.0-draft

Citations

Add authoritative sources relevant to this calculator (standards bodies, manuals, official docs).

Changelog

0.1.0-draft — 2026-01-19: Initial draft (review required).