1. Definition
The slope is k=(y₂−y₁)/(x₂−x₁)=tanα; undefined when x₁=x₂ (vertical).
3. Properties & Laws
- Rise over run;
- k=tanα;
- Vertical undefined, horizontal 0;
- Sign gives rise/fall.
4. Steps
- Enter two points;
- Click "Slope";
- Or click "Load Example".
5. Worked Examples
Example: (1,1),(4,7): k=2.
6. Common Pitfalls
Zero denominator undefined;
Match rise and run;
Order-independent.