Question

On a coordinate plane, a triangle has points A prime (6, 8), B prime (10, negative 6), and C prime (6, negative 6).
What is the pre-image of vertex A' if the image shown on the graph was created by a reflection across the y-axis?

(–8, –6)
(–6, 8)
(8, 6)
(6, –8)

Answer 1

(-6, 8)

Reflection across the y-axis maps (x, y) → (−x, y), so the pre-image of A'(6, 8) is (−6, 8).