Integrax User Guide

Integrax is a 2D graphing calculator for plotting functions, inspecting values, and exploring intersections and integrals.

Quick Start

1. Run the app.
2. Type expressions in the left panel.
3. Press Enter in a field to update the graph.

Core Features

• Plot functions of x: x^2, sin(x), x^3 - 4x
• Multiple functions at once (each entry is a separate expression)
• Zoom with mouse wheel (zoom centers on cursor)
• Pan by dragging the graph
• Mouse coordinate readout at the bottom right
• Click near a curve to snap and label a point (click again to toggle label)
• Intersections between functions are marked with dots
• Click intersection dots to toggle labels (multiple labels supported)
• Axis intercepts (x- and y-intercepts) are marked as dots

Expression Syntax

Functions

Use x as the variable:

• x^2
• sin(x)
• x^3 - 2x + 1

Named Functions

Define reusable functions:

• f(x)=x^2+1
• g(x)=f(x)+3

Then use them in other expressions:

• f(x)
• g(x)

Derivatives

Use a prime on a named function:

• f'(x)

Derivatives are computed numerically.

Vertical and Horizontal Lines

• Horizontal line: y = 3
• Vertical line: x = 2

Domain and Range Constraints

Add constraints in curly braces:

• x^2 { -2 < x < 3 }
• sin(x) { x <= 6.28 && y >= -0.5 }

Supported operators: <, <=, >, >=
Use && to combine constraints.

Definite Integrals

Compute numeric definite integrals:

• int(x^2+1, 0, 3)
• int(f(x), 0, 1)

Integrals are computed numerically.

Integral Shading and Area Labels

If an expression contains int(...), Integrax shades the area under the integrand from a to b (between the curve and the x-axis).

Click a shaded region to toggle an area label at the click position.

Controls

• Pan: click and drag
• Zoom: mouse wheel
• Clear clicked labels: Esc

Notes

• All numeric results are approximate.
• Invalid expressions are ignored (not plotted).