The adage, a picture is worth a thousand words, rings particularly true when it comes to mathematics. Sometimes you just need to “see it” before you can fully understand it.
Jenn, Founder Calcworkshop®, 15+ Years Experience (Licensed & Certified Teacher)
Well, this lesson is all about making an equation come to life graphically. We will start with laying the foundation for how we graph all equations, or functions; the Coordinate Plane.
What is the coordinate grid?
Well, the coordinate grid, sometimes referred to as the Cartesian or rectangular coordinate plane, is the intersection of two real number lines, one horizontal and one vertical. It acts as a map and yields precise directions from one place to another.
And just like a map has a compass rose which indicates north-south-east-west directions, the coordinate plane is divided into Quadrants or regions that help us to identify where on the plane, or map, a particular point is located.
Coordinate Plane with Quadrants
These directions, or addresses, are referred to as ordered pairs or coordinates and are used to graph equations.
Each ordered pair has both an x-and y-coordinate, similar to having a house number and street name for identifying a particular building.
Now, just like when we read a map, we need a place to start. In graphing, we always start at the origin, which is the intersection of our two real number lines.
Then we use the ordered pair to determine our horizontal and vertical movements. As Math Planet so nicely states, the x-coordinate tells us how many steps from the origin we will go either left or right, negative or positive directions respectively.
And the y-coordinate tells us how many steps to move up or down, again positive or negative directions.
Together we will learn how to plot points (graph points) on the coordinate plane, graph equations given two points, and identify if an equation is linear or not.
Coordinate Plane Explained – Video
Get access to all the courses and over 450 HD videos with your subscription
Monthly and Yearly Plans Available
Still wondering if CalcWorkshop is right for you?
Take a Tour and find out how a membership can take the struggle out of learning math.