Graph y = 2/x from y = 1/x

Step by step

The question

Question: graph y = 2/x from y = 1/x.

We know the graph of y = 1/x.

It is two curves, one in each corner.

1 Read the changes

The 2 in front makes every y 2 times as big.

The graph gets steeper.

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

(−1, −1) goes to (−1, −2).

(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 = 0 and y = 0.

Join the new points with the same shape.

This is y = 2 over x.

5 Check

Let's check.

Put x = 1 in the new rule.

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

And x = −1 gives y = −2: the point (−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.