Now, the area of the region OAQBO bounded by curves y2 = 4x and x2 = 4y =
2
4
0
2
x4
x
dx


−




∫
 = 
4
3
3
2
0
2
2
3
x12
x


×
−






= 32
16
16
3
3
3
−
= (1)
Again, the area of the region OPQAO bounded by the curves x2 = 4y, x = 0, x = 4
and x-axis
=
2
4
4
3
0
0
1
16
4
12
3
x
dx
x

=
=


∫ (2)
Similarly, the area of the region OBQRO bounded by the curve y2 = 4x, y-axis,
y = 0 and y = 4
=
2
4
4
4
3
0
0
0
1
16
4
12
3
y
xdy
dy
y

=
=
=


∫
∫