Question

What are the coordinates of the triangle (ABC) when reflected across the y-axis?

A. A'(−2, 4), B'(−6, 2), C'(−2, −6)
B. A'(2, 4), B'(6, 2), C'(2, −6)
C. A'(−1, 3), B'(−3, 1), C'(−1, −3)
D. A'(−2, −4), B'(−6, −1), C'(1, 6)

Answer 1

9514 1404 393

Answer:

A. A'(−2, 4), B'(−6, 2), C'(−2, −6)

Explanation:

Reflection across the y-axis negates the x-coordinate:

(x, y) ⇒ (-x, y) . . . . reflection across the y-axis

Looking at the answer choices, we see that they all differ in A', so we can make the appropriate choice just by looking at point A

A(2, 4) ⇒ A'(-2, 4) . . . . matches choice A