Step by step
The question
Question: graph y = √(x + 1) + 2 from y = √x.
We know the graph of y = √x.
It is half a U, lying on its side.
1 Read the changes
Inside, next to x, we have + 1.
x = −1 makes the inside 0.
So the start point moves to x = −1: left 1.
Outside, at the end, + 2 adds 2 to every y.
So the graph moves up 2.
Careful!
Inside, it goes the opposite way to the sign.
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 left 1.
Then up 2.
(0, 0) goes to (−1, 2).
(1, 1) goes to (0, 3).
(4, 2) goes to (3, 4).
4 Draw the new graph
Join the new points with the same shape.
This is y = √(x + 1) + 2.
5 Check
Let's check.
Put x = −1 in the new rule.
We get y = 2: the point (−1, 2) we drew.
And x = 3 gives y = 4: the point (3, 4).
Let's look back.
First: read the changes.
Then: start from y = √x.
Then: move the points.
Then: draw the new graph.
Last: check.