Q59 / 100 · BITSAT 2024 (Memory Based Paper 2) · Mathematics
The area of the region bounded by the curves $x$ $=y^2-2$ and $x=y$ is
- A$\frac{9}{4}$
- B$9$
- Correct answerC$\frac{9}{2}$
- D$\frac{9}{7}$
Solution
Given, $x=y^2-2$ and $x=y$.
On solving, $x=y^2-2$ and $x=y$, we get $(-1,-1)$ and $(2,2)$.
Area of the shaded region,
$\begin{aligned}
& A=\int_{-1}^2 y d y-\int_{-1}^2\left(y^2-2\right) d y \\
& =\left[\frac{y^2}{2}-\frac{y^3}{3}+2 y\right]_{-1}^2=\left(\frac{4}{2}-\frac{8}{3}+4\right)-\left(\frac{1}{2}+\frac{1}{3}-2\right) \\
& =\frac{10}{3}+\frac{7}{6}=\frac{27}{6}=\frac{9}{2} .
\end{aligned}$
On solving, $x=y^2-2$ and $x=y$, we get $(-1,-1)$ and $(2,2)$.
Area of the shaded region,
$\begin{aligned}
& A=\int_{-1}^2 y d y-\int_{-1}^2\left(y^2-2\right) d y \\
& =\left[\frac{y^2}{2}-\frac{y^3}{3}+2 y\right]_{-1}^2=\left(\frac{4}{2}-\frac{8}{3}+4\right)-\left(\frac{1}{2}+\frac{1}{3}-2\right) \\
& =\frac{10}{3}+\frac{7}{6}=\frac{27}{6}=\frac{9}{2} .
\end{aligned}$Hence, the correct answer is option: 'C'.