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Graph y = |x - 1| + 2 from y = |x|

Step by step, with the reason for every step · Graph transformations · Algebra 2

Step by step

The question

Question: graph y = |x − 1| + 2 from y = |x|.

y = |x − 1| + 2

We know the graph of y = |x|.

It is a V, with its corner at (0, 0).

we know: y = |x|

1 Read the changes

Inside, next to x, we have − 1.

x = 1 makes the inside 0.

So the corner moves to x = 1: right 1.

x − 1 inside → right 1

Careful!

Inside, it goes the opposite way to the sign.

Careful: − 1 inside goes right, not left

Outside, at the end, + 2 adds 2 to every y.

So the graph moves up 2.

+ 2 outside → up 2

2 Start from y = |x|

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.

Draw y = |x| first.

Its corner is at (0, 0).

3 Move the corner

Move it right 1.

Then up 2.

The new corner is (1, 2).

4 Draw the new graph

The shape stays the same.

From the corner, 1 right, 1 up.

And 1 left, 1 up.

Join them with the same V.

This is y = |x − 1| + 2.

5 Check

Let's check.

Put x = 1 in the new rule.

We get y = 2: the corner (1, 2).

x = 1: y = |1 − 1| + 2 = |0| + 2 = 0 + 2 = 2

And x = 2 gives y = 3: the point (2, 3) we drew.

x = 2: y = |2 − 1| + 2 = |1| + 2 = 1 + 2 = 3

Let's look back.

First: read the changes.

Then: start from y = |x|.

Then: move the corner.

Then: draw the new graph.

Last: check.

Answer
+ 2 outside → up 2

Your turn

Try this one yourself, then check:

graph y = |x − 1| + 5 from y = |x|
Show the answer
corner (1, 5)

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