Draw perpendicular
BM to the x-axis Therefore, the required area = area of
the region OBMO + area of the region
BMAB Now, the area of the region OBMO
= 
4
4
0
0
ydx
xdx
=
∫
∫ (3)
= 
4
2
0
1
2 x




= 8
Fig 8