Steply

Graph y = 1/(x - 3) - 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 − 3) − 1 from y = 1/x.

y = 1x − 3 − 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 − 3.

x = 3 makes the inside 0.

So the center moves to x = 3: right 3.

x − 3 inside → right 3

Outside, at the end, − 1 takes 1 away from every y.

So the graph moves down 1.

− 1 outside → down 1

Careful!

Inside, it goes the opposite way to the sign.

Careful: − 3 inside goes right, not left

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 right 3.

Then down 1.

(−1, −1) goes to (2, −2).

(1, 1) goes to (4, 0).

4 Draw the new graph

1/x never touches the axes.

Those two lines move too.

Now it never touches x = 3 and y = −1.

Join the new points with the same shape.

This is y = 1/(x − 3) − 1.

5 Check

Let's check.

Put x = 4 in the new rule.

We get y = 0: the point (4, 0) we drew.

x = 4: y = 14 − 3 − 1 = 11 − 1 = 1 − 1 = 0

And x = 2 gives y = −2: the point (2, −2).

x = 2: y = 12 − 3 − 1 = 1−1 − 1 = −1 − 1
= −2

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 → down 1

Your turn

Try this one yourself, then check:

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

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