Steply

Graph y = 1/(x + 2) + 1 from y = 1/x

Step by step, with the reason for every step · Other parent graphs · Algebra 2

Step by step

The question

Question: graph y = 1/(x + 2) + 1 from y = 1/x.

y = 1x + 2 + 1

We know the graph of y = 1/x.

It is two curves, one in each corner.

we know: y = 1/x

1 Read the changes

Inside, next to x, we have + 2.

x = −2 makes the inside 0.

So the center moves to x = −2: left 2.

x + 2 inside → left 2

Outside, at the end, + 1 adds 1 to every y.

So the graph moves up 1.

+ 1 outside → up 1

Careful!

Inside, it goes the opposite way to the sign.

Careful: + 2 inside goes left, not right

2 Start from y = 1/x

Draw the grid.

Draw y = 1/x first.

It goes through (−1, −1) and (1, 1).

3 Move the points

The center (0, 0) moves left 2.

Then up 1.

(−1, −1) goes to (−3, 0).

(1, 1) goes to (−1, 2).

4 Draw the new graph

1/x never touches the axes.

Those two lines move too.

Now it never touches x = −2 and y = 1.

Join the new points with the same shape.

This is y = 1/(x + 2) + 1.

5 Check

Let's check.

Put x = −1 in the new rule.

We get y = 2: the point (−1, 2) we drew.

x = −1: y = 1−1 + 2 + 1 = 11 + 1 = 1 + 1 = 2

And x = −3 gives y = 0: the point (−3, 0).

x = −3: y = 1−3 + 2 + 1 = 1−1 + 1 = −1 + 1
= 0

Let's look back.

First: read the changes.

Then: start from y = 1/x.

Then: move the points.

Then: draw the new graph.

Last: check.

Answer
+ 1 outside → up 1

Your turn

Try this one yourself, then check:

graph y = 1x + 3 + 3 from y = 1/x
Show the answer
center (−3, 3), through (−2, 4)

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