Step 1: Find the co-ordinates of P′
Given: Co-ordinates of P=(−8,1)
P is reflected in the x-axis to the point P′.
Reflection in the x-axis, Mx(x,y)=(x,−y)
⇒Mx(−8,1)=(−8,−1)
So, the co-ordinates of P′ are (−8,−1).
Step 2: Find the co-ordinates of P′′
P′ is reflected in the origin to point P′′.
Reflection in the origin, Mo(x,y)=(−x,−y)
⇒Mo(−8,−1)=(8,1)
So, the co-ordinates of P′′ are (8,1).
Step 3: State the single transformation that maps P into P′′
Co-ordinates of P=(−8,1)
Co-ordinates of P′′=(8,1)
On reflection, only the sign of the abscissa
(x-coordinate) has changed.
Reflection in the y-axis, My(x,y)=(−x,y)
Hence, the single transformation that maps P onto P′′ is reflection in the y-axis.