Question

The point P(a, b) is first reflected in the origin and then reflected in the y-axis to P’. If P’ has co-ordinates (4, 6); evaluate a and b.

Answer 1

M_O (a, b) = (–a, –b)

M_y (–a, –b) = (a, –b)

Thus, we get the co-ordinates of the point P’ as (a, –b). It is given that the co-ordinates of P’ are (4, 6).

On comparing the two points, we get, a = 4 and b = –6