Question

What are the coordinates of X'? OA) (5, -1) OB) (-5, -1) OD) (5, 1) OC) (-5, 1)

Answer 1

Reflection of a figure

If we want to reflect a point across y-axis, we should treat it as a mirror:

As we can observe, in order to reflect it we just must change the sign its x coordinate.

(x, y) ↔ (-x, y)

Then, if we wanted to reflect the point X, since its coordinates are (-5, -1)

we must change the sign of the x=-5:

X(-5 , -1) ↔ X'(5, -1)

Answer: X'(5, -1)