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Graph y = √x + 4 from y = √x

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

Step by step

The question

Question: graph y = √x + 4 from y = √x.

y = √x + 4

We know the graph of y = √x.

It is half a U, lying on its side.

we know: y = √x

1 Read the changes

Outside, at the end, + 4 adds 4 to every y.

So the graph moves up 4.

+ 4 outside → up 4

2 Start from y = √x

Draw the grid.

Draw y = √x first.

It goes through (0, 0), (1, 1) and (4, 2).

3 Move the points

The start point (0, 0) moves up 4.

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

(1, 1) goes to (1, 5).

(4, 2) goes to (4, 6).

4 Draw the new graph

Join the new points with the same shape.

This is y = √x + 4.

5 Check

Let's check.

Put x = 0 in the new rule.

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

x = 0: y = √0 + 4 = 0 + 4 = 4

And x = 4 gives y = 6: the point (4, 6).

x = 4: y = √4 + 4 = 2 + 4 = 6

Let's look back.

First: read the changes.

Then: start from y = √x.

Then: move the points.

Then: draw the new graph.

Last: check.

Answer
+ 4 outside → up 4

Your turn

Try this one yourself, then check:

graph y = √x + 2 from y = √x
Show the answer
start point (0, 2), through (4, 4)

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