Question

The point V(x,y) is first reflected in the X-axis and then reflected in the origin to V'. If V' has coordinates (8,9); find x and y.

• A. x = -8, y = 9
• B. x = -8, y = -9
• C. x = 8, y = -9
• D. x = 8, y = 9

Answer 1

The correct option is A

x = -8, y = 9

Let V1 be the reflection of V in X-axis.

When a point M (x,y) is reflected in the X-axis the sign of the ordinate changes.

Hence, V(x,y) transforms $\to$ V1(x,-y)

When a point M (x,y) is reflected in the origin the sign of both abscissa and ordinate changes.

V1(x,-y) transforms $\to$ V'(-x,y)

we know V'(8,9)

Hence x = -8, y = 9