Reflecting a point in the y-axis

Difficulty Stretch · Set qpeskm

Give each new point as x, y.

Fill in what you can and press Check. Nothing you type is sent anywhere.

1
Reflect (-17, -21) in the y-axis.
2
Reflect (16, 13) in the y-axis.
3
Reflect (-22, 10) in the y-axis.
4
Reflect (-27, 8) in the y-axis.
5
Reflect (-11, -20) in the y-axis.
6
Reflect (13, 20) in the y-axis.
7
Reflect (19, 20) in the y-axis.
8
Reflect (30, -11) in the y-axis.
9
Reflect (29, 14) in the y-axis.
10
Reflect (1, -12) in the y-axis.
11
Reflect (14, -21) in the y-axis.
12
Reflect (20, 7) in the y-axis.
13
Reflect (-18, 24) in the y-axis.
14
Reflect (-19, 27) in the y-axis.
15
Reflect (3, 2) in the y-axis.
16
Reflect (11, -24) in the y-axis.
17
Reflect (8, -24) in the y-axis.
18
Reflect (-13, -26) in the y-axis.
19
Reflect (-10, -21) in the y-axis.
20
Reflect (-30, 21) in the y-axis.

What is in this set

The numbers in this set run from 1 to 30.
A careful solution takes 2 written steps on average.
The mistake this set invites most often, in 100% of the problems: a reflection in the y-axis leaves the y coordinate alone and changes the sign of the other one.
Answers are a short answer exactly as the problem asks for it.

Drawing 240 problems from this page produced 233 different ones, 97% — so a sheet of 20 is a new sheet almost every time.

The same skill, harder or easier

We would put this in front of a grade 6 class. That is our judgement, not a standard, and it is printed here so you can disagree with it. Everything else we put in that year.