Graph y = 3 using a table

Step by step

The question

Question: graph y = 3 using a table of values.

We pick some x values.

We work out y for each one.

Each x and y make a point.

1 Choose x values

We pick three easy x values: −1, 0 and 1.

Two points make a line.

The third one checks them.

2 Work out y

There is no x.

So y is 3 for every x.

3 Plot the points

Draw the grid.

Each column is a point: x on top, y under it.

The first one is (−1, 3).

Put a dot.

(0, 3).

Dot.

(1, 3).

Dot.

Careful!

y = 3 is not x = 3.

Every point has y = 3, so the line is flat, not up and down.

4 Draw the line

The three dots line up.

Join the dots with a straight line.

It keeps going both ways.

5 Check

Let's check with one more x: x = 2.

We get y = 3.

The point (2, 3) is on our line.

So the graph is right!

Let's look back.

First: choose x values.

Then: work out y.

Then: plot the points.

Then: draw the line.

Last: check.