Question

If ∆QRS with vertices Q(4, 2), R(5, 1), S(3,7) is reflected across the y-axis, what will S' be?

A) S'(-3, 7)
B) S'(3, -7)
C) S'(5, 7)
D) S'(3, 7)

Answer 1

When reflecting point S(3,7) across the y-axis, the x-coordinate changes sign, resulting in S'(-3, 7). The correct answer is A) S'(-3, 7).

Step-by-step explanation:

When reflecting a point across the y-axis, the x-coordinate of the point changes sign, but the y-coordinate remains the same. This is because the y-axis functions as a mirror, so the point's position vertically does not change, only its position horizontally does as it moves across to the other side of the y-axis.

For point S with coordinates (3,7), reflection across the y-axis will result in S' having coordinates (-3,7).

Therefore, the correct answer is A) S''(-3, 7).