Q57 / 155 · WBJEE 2024 · Mathematics
The area bounded by the curves $x=4-y^2$ and the $Y$-axis is
- A16 sq. unit
- Correct answerB$\frac{32}{3}$ sq. unit
- C$\frac{16}{3}$ sq. unit
- D32 sq. unit
Solution
Hint: $x=4-y^2 \Rightarrow y^2=-x+4$
$x=0 \Rightarrow y^2=4 \Rightarrow y= \pm 2$
Area bounded by the curve $x=4-y^2$ and $y$-axis is,
$=2 \int_0^2 x d y=2 \int_0^2\left(4-y^2\right) d y=2\left[4 y-\frac{y^3}{3}\right]_0^2=2\left(8-\frac{8}{3}\right)=\frac{32}{3}$ sq. unit
$x=0 \Rightarrow y^2=4 \Rightarrow y= \pm 2$
Area bounded by the curve $x=4-y^2$ and $y$-axis is,
$=2 \int_0^2 x d y=2 \int_0^2\left(4-y^2\right) d y=2\left[4 y-\frac{y^3}{3}\right]_0^2=2\left(8-\frac{8}{3}\right)=\frac{32}{3}$ sq. unitHence, the correct answer is option: 'B'.