Coordinate Geometry
Use the distance and midpoint formulas.
The rules
- Distance = √((x₂ − x₁)² + (y₂ − y₁)²).
- Midpoint = ((x₁ + x₂)/2, (y₁ + y₂)/2).
- A circle with center (h, k) has equation (x − h)² + (y − k)² = r².
- Slopes tell you whether lines are parallel or perpendicular.
Watch out: Forgetting to square root at the end of the distance formula.
Worked example
What is the distance between (1, 2) and (4, 6)?
- Differences: 3 and 4.
- √(9 + 16) = 5.
Answer: 5
Try it yourself
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