Question
Mathematics Question on applications of integrals
Area lying between the curve y2=4x and y=2x is
A
32
B
31
C
41
D
43
Answer
31
Explanation
Solution
The area lying between the curve,y2=4x and y=2x,is represented by the shaded
area OBAO as
The points of intersection of these curves are O(0,0)and A(1,2).
We draw AC perpendicular to x-axis such that the coordinates of C are(1,0).
∴Area OBAO=Area(ΔOCA)-Area(OCABO)
=
\int_{0}^{4} 2x \,dx - $$$$\int_{0}^{4} 2\sqrt{x} \,dx
=2[2x2]10-2[x3/2/3/2]10
=|1-34|
=|-31|
=31units
Thus, the correct answer is B.