What you’ll learn
Perform reflections on coordinates.
Key idea
Coordinate-axis mirrors negate the perpendicular coordinate; the mirror y=x swaps coordinate roles.
Axis mirrors negate perpendicular coordinate; y=x swaps coordinates, with no arbitrary oblique mirror inference.
Worked example
Enter the exact value or ordered values in the format requested below.
Read image I after reflecting P across x-axis. Enter I's coordinate pair.
Marked coordinates: I=(-2, 3); P=(-2, -3).
- The named mirror x-axis follows (x,y)→(x,-y); apply this same rule to each original vertex.
- Image vertices are [(-2, 3), (0, 3), (-2, 1)]; corresponding distances and perpendicular mirror alignment are preserved.
Answer: (-2,3)
Quick Check
Relate the graph used in 'Perform reflections on coordinates' to an equation, table, transformation, or verbal description.
Connect image graph and mapping rows [((-1, 2), (1, 2)), ((1, 2), (-1, 2)), ((-1, 4), (1, 4))] to their common reflection line and rule.
Marked coordinates: P=(-1, 2); I=(1, 2).