2D Coordinates
What is the Cartesian plane?
- The Cartesian plane is a two-dimensional grid that has
- a horizontal scale, called the x-axis
- a vertical scale, called the y-axis
- The two axes meet at the origin
- where x and y are both 0
What are coordinates?
- Coordinates are a pair of numbers, x and y , that describe the location of a point on the grid
- They are written in brackets as (x , y )
- The point is
- x units on the horizontal scale
- y units on the vertical scale
- The origin is (0, 0)
- Positive values of x are to the right of the origin
- Negative values are to the left
- Positive values of y are above the origin
- Negative values are below
- Positive values of x are to the right of the origin
- For example, from the origin:
- (2, 5) is the point 2 units to the right and 5 units up
- (-1, -4) is the point 1 unit to the left and 4 units down
- "Along the corridor, up the stairs" helps to remember horizontal then vertical, (x , y )
Examiner Tip
- Check the scale on the coordinate grid!
- 1 square might not be 1 unit.
Worked example
A is 4 units up, so y is 4
Give your answer in brackets
Count 3 units right and two units down
Mark the point with a solid circle or cross and label it B