(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

=
=
=


∫
∫ (3)
From (1), (2) and (3), it is concluded that the area of the region OAQBO = area of
the region OPQAO = area of the region OBQRO, i e , area bounded by parabolas
y2 = 4x and x2 = 4y divides the area of the square in three equal parts