# Graphing Lines using a Table of Values - Concept

###### Explanation

When first introduced to graphing lines, we often use a table of values to plot points and connect them. There are several other methods of **graphing lines**, including using a point and the slope. Sometimes graphing lines using an equation involves the same methods as using a table of values. Since we graph lines in the coordinate plane, it is necessary to understand how to connect graphs, tables and equations.

###### Transcript

There are different methods you could use to

go from an equation to a graph.

Making a table is one of the most fundamental

or basic level strategies for

graphing a line.

And, by the way, making a table will work

when you start moving through your

high school career and getting into other

types of equations like curves.

You can make a table for them also.

But let's check it out for lines.

When you want to graph a line by making a

table, keep in mind any point represents

a solution to the equation.

And here's what I mean.

Every point has an X number

and a Y number. When I input an X number into

my equation,my Y value's my output.

So any point that's on the line is

a true solution to that equation.

That becomes useful when

you're making a table.

Tables usually look like this.

You can either make them horizontally or

vertically like that, if you want to.

Totally up to your preference.

And what you do is you choose

any X numbers you want to.

It's usually a good idea to use some negative

values in addition to some positive

values. And then what you do is one by one you're

going to substitute these X numbers

into your equation as inputs to find

your corresponding Y value output.

Then each one of these is going to turn

into a point on your graph and you'll

just connect them using a ruler.

One thing I want to make sure I point

out to you guys before you start this

process is that you want your

points to be ruler-straight.

Here's what I mean.

Let's say I get my points on there and

they kind of look like this and I have

one that's kind of like out there.

Well, these three are straight.

So that's probably what

the line looks like.

But this point, I probably made an error.

If I got three that are perfectly lined

up, they're ruler-straight and I used

a ruler to draw them and I have this

point, that's just like a little

bit off, chances are I made

an error in my table.

So go back to your table and make corrections.

Most people tend to do at least three

points in their table to start with.

I would recommend for your first tables

you start doing, you start by doing

about five points.

And, again, you're going to substitute your

X numbers in to find your Y values

and then put those

dots on the graph.

They should make a ruler-straight line.