Step by step
The question
Question: graph x = −4.
A new word: vertical.
It means straight up and down.
1 Read the equation
x = −4 has no y in it.
So y can be any number.
But x is always −4.
2 Make points
Let's make some points.
Every point has x = −4.
For y, we pick any numbers: −2, 1 and 3.
3 Plot the points
Draw the grid.
The x-axis goes across.
The y-axis goes up and down.
They meet at 0.
That point is called the origin.
Put the points on the grid: (−4, −2),
(−4, 1),
and (−4, 3).
They stand in a column, right above each other.
4 Draw the line
Join the dots.
The line goes straight up and down.
It is a vertical line.
It never goes across, so we call its slope undefined.
It crosses the x-axis at −4.
So x = −4 is a vertical line.
Careful: x = −4 is not a flat line.
It goes up and down.
5 Check
Let's check one more point on the line: (−4, 2).
Its x is −4.
So it fits x = −4.
The line is right!
Let's look back.
First: read the equation.
Then: make points.
Then: plot the points.
Then: draw the line.
Last: check.