Documentation — Graphing Calculator Guide

Getting Started

graphingcalculate.com is a free, browser-based graphing calculator. No account, download, or payment is required. Simply visit /calculator and start entering equations immediately.

Entering Expressions

The expression panel on the left accepts standard mathematical notation. The rich math input (powered by MathLive) renders equations in proper typeset notation as you type.

Supported Equation Forms

• y = x^2 + 2x - 1 — explicit function of x
• f(x) = sin(x) — function notation
• y = a*x + b — parametric with sliders (a, b become sliders)
• r = 2 + cos(θ) — polar equations (enable Polar mode first)

Supported Functions

• Trigonometric: sin, cos, tan, asin, acos, atan
• Exponential/Log: exp(x), log(x), log2(x), log10(x)
• Algebra: sqrt(x), abs(x), floor(x), ceil(x), sign(x)
• Constants: pi, e

Graphing Basics

Interact with the graph canvas using these gestures:

• Pan: Click and drag anywhere on the canvas
• Zoom: Scroll the mouse wheel (or pinch on touch devices)
• Trace: Hover over a curve to see exact coordinates
• Tangent line: Hold Shift while hovering to display the derivative/slope at that point

Special points — roots, maxima, minima, and intersections — are detected automatically and marked on the graph.

Dynamic Sliders

When you include an unknown variable other than x in an expression (e.g. y = a * sin(b * x)), a slider automatically appears beneath the expression for each parameter. Drag the slider to change the value in real-time and watch the graph update instantly.

You can customise the slider range and step size via the slider controls.

Calculus Tools

Tangent Lines

Hold Shift while hovering over any curve. A dashed tangent line is drawn at the cursor position, and the instantaneous slope (derivative value) is shown in the coordinate display. The derivative is computed numerically using the central difference formula.

Definite Integrals

1. Click the ∫ Integral button in the toolbar (or press I)
2. Click on the canvas to set the lower bound (a)
3. Click again to set the upper bound (b)
4. The area under the curve is shaded and the computed value is displayed in a badge

Integration is computed using Simpson's Rule with 1,000 sub-intervals for high accuracy.

Data Tables & Regression

Click "+ Add table" in the expression panel footer to insert a data table. Enter X and Y values into the grid — your data points are plotted as coloured scatter dots on the canvas immediately.

Enable "Show linear regression" to fit a best-fit line to your data. The equation y = mx + b and R² coefficient are displayed below the table.

Polar Mode

Enable polar coordinates from the Settings panel (gear icon). In polar mode, enter equations in the form r = f(θ). Examples:

• r = 2 — circle with radius 2
• r = 1 + cos(θ) — cardioid
• r = cos(2 * θ) — four-petal rose
• r = θ / (2 * pi) — Archimedean spiral

Export & Sharing

Open the Export menu (Ctrl/⌘ + E) to:

• PNG: Download a high-resolution raster image of your graph
• SVG: Download a vector image for print or web embedding
• LaTeX: Copy the equations as LaTeX-formatted math for use in papers or slides
• Share URL: The current URL always encodes your graph state — just copy and share it

Keyboard Shortcuts