Reading coordinates
Read the x-value first, then the y-value to name any plotted point.
Coordinate Grid
Plot and move points on a clean coordinate plane with labels and gridlines.
Plot a point and reflect it
Start with point A, then watch its reflection across the y-axis. The grid shows what changes and what stays the same.
Current transformation
Point A moves from Quadrant I to A′ in Quadrant II.
Reflect across the y-axis flips left and right.
The x-coordinate changes sign, but the y-coordinate stays the same.
Try this next
Point A is at (2, 3)
Reflect across the y-axis to get A′ at (-2, 3).
Quick reference
Mini lesson
Explore coordinates, quadrants, and reflections by dragging points on the grid.
Exploring quadrants
Positive and negative coordinates place points in different parts of the plane.
Explore further
Try these next
#1
Plot a point
Move the point to (3, 4).
#2
Try a reflection
Place a point at (4, 2), then reflect it across the y-axis.
#3
Find a quadrant
Move the point to Quadrant III.
Keep going