JEE PYQ: Area Under Curves Question 4
Question 4 - 2021 (18 Mar Shift 2)
The area bounded by the curve $4y^2 = x^2(4-x)(x-2)$ is equal to:
(1) $\frac{\pi}{8}$
(2) $\frac{3\pi}{8}$
(3) $\frac{3\pi}{2}$
(4) $\frac{\pi}{16}$
Show Answer
Answer: (3) $\frac{3\pi}{2}$
Solution
Domain $x \in [2,4]$. Using the property $\int_a^b f(x),dx = \int_a^b f(a+b-x),dx$: $A = 3 \cdot \frac{\pi}{2} \cdot 1^2 = \frac{3\pi}{2}$.