A student observes an open-air honeybee nest on the branch of a tree, whose plane figure is parabolic shape given by $x^2 = 4y$. Then the area (in square units) of the region bounded by parabola $x^2 = 4y$ and the line $y = 4$ is: |
$\frac{32}{3}$ $\frac{64}{3}$ $\frac{128}{3}$ $\frac{256}{3}$ |
$\frac{64}{3}$ |
The correct answer is Option (2) → $\frac{64}{3}$ The required region is symmetric about the y-axis. So, required area (in sq. units) is: $= 2 \int\limits_{0}^{4} x \, dy = 2 \int\limits_{0}^{4} 2\sqrt{y} \, dy = 4 \left[ \frac{y^{\frac{3}{2}}}{\frac{3}{2}} \right]_{0}^{4} = \frac{64}{3}$ |