Fig 8 18
Fig 8 19
APPLICATION OF INTEGRALS         371
Required area of the enclosed region OACA′O between circles
= 2 [area of the region ODCAO]
(Why )
= 2 [area of the region ODAO + area of the region DCAD]
= 
1
2
0
1
2
y dx
y dx


+




∫
∫
= 
1
2
2
2
0
1
2
4
(
2)
4
x
dx
x dx


−
−
+
−




∫
∫
(Why