Finding Points on a Coordinate Plane
The coordinate plane is formed by two intersecting number lines: the horizontal x-axis and the vertical y-axis. The point where they intersect is called the origin, and is marked as (0, 0). The numbers that identify a point on a coordinate plane are called an ordered pair, and they always are written in the same order: first is the location along the x-axis, and second is the location along the y-axis.
One way to think about the coordinate plane is to break it up into four parts. The two axes divide the coordinate plane into four quadrants:
Quadrant I is in the upper right region, where both x and y values are positive. For example, the point (2, 3) lies in Quadrant I in this coordinate plane:
Quadrant II is in the upper left region, where x values are negative and y values are positive. For example, the point (-3, 4) is in Quadrant II here:
Quadrant III contains points with negative x and y values and is the lower left region. The point (-5, -2) lies in Quadrant III:
Quadrant IV contains points with a positive x value but negative y value and is the lower right region. For instance, (4, -6) is in Quadrant IV:To plot a point and find its coordinates:
- First identify the x and y values. Let's use the point (-2,5) as an example.
- Look along the x-axis and go left 2 units from the origin.
- Then go up 5 units from the origin along the y-axis.
- Where those values intersect is the point (-2,5):