The coordinates of a point are a pair of numbers that define its exact location on a two-dimensional plane. We already know that the coordinate plane has two axes at right angles to each other, called the *x* and *y axis*. The coordinates of a given point represent how far along each axis the point is located.

The coordinates are written as an **"ordered pair".**

The letter P is simply the name of the point and is used to distinguish it from others. The two numbers in parentheses are the x and y coordinate of the point.

1. The first number (x) specifies how far along the x (horizontal) axis the point is.

2. The second is the y coordinate and specifies how far up or down the y axis to go.

The sign of the coordinate is important. A positive number means to go to the right (x) or up (y). Negative numbers mean to go left on x axis or down to the y axis

Each point on a number line is assigned a number. In the same way, each point in a plane is assigned a pair of numbers.

The *x*‐axis and *y*‐axis separate the coordinate plane into four regions called quadrants.

- The upper right quadrant is quadrant I
- The upper left quadrant is quadrant II
- The lower left quadrant is quadrant III
- The lower right quadrant is quadrant IV.

*x*‐coordinate :

The number to the left of the comma in an ordered pair is the *x*‐coordinate of the point and indicates the amount of movement along the *x*‐axis from the origin. The movement is to the right if the number is positive and to the left if the number is negative.

*y*‐coordinate :

The number to the right of the comma in an ordered pair is the *y*‐coordinate of the point and indicates the amount of movement perpendicular to the *x*‐axis. The movement is above the *x*‐axis if the number is positive and below the *x*‐axis if the number is negative.