Math 1310
Section 1.1: Points, Regions, Distance and Midpoints
In this section, we’ll review plotting points, graph horizontal and vertical lines, some inequalities.
Develop a formula for finding the distance between two points in the coordinate plane and one for
finding the midpoint of a line segment with given endpoints.
Graphing Points and Regions
Here’s the coordinate plane:
As we see the plane consists of two perpendicular lines, the
x-axis
and the
y-axis
. These two lines separate them
into four regions, or
quadrants.
The pair, (
x
,
y
), is called an
ordered pair
. It corresponds to a single unique
point in the coordinate plane. The first number is called the
x
coordinate
, and the second number is
called the
y
coordinate
. The ordered pair (0, 0) is referred to as the
origin
. The
x
coordinate
tells us the
horizontal distance a point is from the origin. The
y
coordinate
tells us the vertical distance a point is
from the origin. You’ll move right or up for positive coordinates and left or down for negative
coordinates.

Example: Plot the following points.