Last updated: July 31, 2026
Graphing Inequalities on a Number Line Calculator
Creators
Dharmendra SinghReviewers
Creators
Dharmendra SinghReviewers
Creators
Dharmendra SinghReviewers
Creators
Dharmendra SinghReviewers
Formula
Map inequality sign to interval: < and > use open bounds; ≤ and ≥ use closed bounds.
Where:
- operator=Operator
- value=Boundary Value
Worked Examples
Strict less-than
Graph x < 4.
- 1Strict inequality excludes boundary
- 2Use open circle at 4
- 3Shade to the left
Inclusive greater-than
Graph x ≥ -2.
- 1Inclusive inequality includes boundary
- 2Use closed circle at -2
- 3Shade rightward
Inclusive less-than
Graph x ≤ 7.
- 1Boundary is included
- 2Closed circle at 7
- 3Shade to negative direction
Introduction
Number-line inequalities become clear when converted to interval notation, shading direction, and endpoint style. This calculator provides all three instantly.
Formula Overview
Graphing Inequalities on a Number Line Calculator uses a deterministic math model based on the calculator logic in calculation.ts.
Map inequality sign to interval: < and > use open bounds; ≤ and ≥ use closed bounds.
Inputs are validated before computation
Outputs are rounded consistently for readable results
Invalid values return safe fallback outputs
Input Guide
Use each input key exactly as defined below to match calculator wiring and test coverage.
- 1
operator: Operator
- 2
value: Boundary Value
Output Guide
These output IDs map directly to the return object keys in calculation.ts.
- 1
intervalNotation: Set-builder result in interval form
- 2
direction: Direction to shade on the number line
- 3
circleType: Open circle for strict, closed for inclusive
Validation Rules
The calculator checks for finite numeric values and applies domain constraints before solving.
Required fields must be present
Domain limits are enforced (for example positive lengths or valid operators)
Invalid or non-finite entries resolve to safe defaults
Use examples to verify expected behavior quickly
How to Use
Enter inputs, run calculation, and interpret the primary output first before reviewing supporting values.
Provide all required inputs
Click calculate
Read primary output first
Use secondary outputs for deeper analysis
Practical Uses
This calculator supports classroom work, engineering checks, and fast verification tasks.
Homework and exam preparation
Design and geometry validation
Spreadsheet cross-checking
Quick scenario analysis
FAQs
What does the Graphing Inequalities on a Number Line Calculator compute?
It computes Interval Notation, Shading Direction, Circle Type from validated input values.
Which inputs are required?
Required inputs are: Operator, Boundary Value.
How are invalid values handled?
If inputs are invalid or out of domain, the calculator returns safe default outputs instead of invalid math.
Are results rounded?
Yes. Numeric values are rounded in calculation.ts (typically to six decimal places).
Can I use negative or decimal values?
Decimals are accepted where mathematically valid; sign/domain constraints are enforced by the calculator logic.
How can I verify results?
Use the worked examples and compare each output key with manual calculations or trusted references.