Coordinates of a Point: Abscissa and Ordinate
Every point on a coordinate plane has a unique "address" made up of two numbers. These numbers are called coordinates, and they tell us exactly where the point is located!
🎯 What Are Coordinates?
Coordinates are two numbers that define the exact position of a point on a coordinate plane.
Think of it like this: Just like your home has an address with a street name and house number, every point has an "address" with two numbers!
- Written as an ordered pair: (x, y)
- Every point has unique coordinates
- The order is always fixed: x first, then y
📝 Notation
When we write a point with its coordinates, we use this format:
A(3, −2)
Point A with coordinates (3, −2)| Part | Meaning |
|---|---|
| A | The name of the point |
| (3, −2) | The coordinates in parentheses |
🔑 The Two Coordinates: Abscissa and Ordinate
ABSCISSA (Абсцисса)
The First Coordinate (x-coordinate)
- Shows the horizontal position
- Distance from the y-axis (with sign)
- Positive (+) if right of y-axis
- Negative (−) if left of y-axis
- Named from Latin meaning "cut off"
Remember: Abscissa = x = Horizontal = First!
ORDINATE (Ордината)
The Second Coordinate (y-coordinate)
- Shows the vertical position
- Distance from the x-axis (with sign)
- Positive (+) if above x-axis
- Negative (−) if below x-axis
- Completes the "address" of the point
Remember: Ordinate = y = Vertical = Second!