JEE PYQ: Area Under Curves Question 18
Question 18 - 2020 (07 Jan Shift 2)
The area (in sq. units) of the region ${(x, y) \in R^2 | 4x^2 \leq y \leq 8x + 12}$ is:
(1) $\frac{125}{3}$
(2) $\frac{128}{3}$
(3) $\frac{124}{3}$
(4) $\frac{127}{3}$
Show Answer
Answer: (2) $\frac{128}{3}$
Solution
$4x^2 = 8x + 12 \Rightarrow (x+1)(x-3) = 0$. $A = \int_{-1}^{3}(8x+12-4x^2),dx = \frac{128}{3}$.