The area (in sq. units) of the bigger portion of region enclosed by the curves $4x^2+9y^2 = 36$ and $2x + 3y = 6$ is |
$\frac{3}{2} (π-2)$ $\frac{3}{2} (3π+2)$ $6π$ $3π+3$ |
$\frac{3}{2} (3π+2)$ |
The correct answer is Option (2) → $\frac{3}{2} (3π+2)$ Ellipse: $\frac{x^{2}}{9}+\frac{y^{2}}{4}=1$; line: $2x+3y=6\Rightarrow y=\frac{6-2x}{3}$. Intersection points: $(0,2)$ and $(3,0)$. Smaller segment area (between ellipse and line): $A_s=\displaystyle\int_{0}^{3}\left(\frac{2}{3}\sqrt{9-x^{2}}-\frac{6-2x}{3}\right)\,dx =\frac{1}{3}\left[2\int_{0}^{3}\sqrt{9-x^{2}}\,dx-\int_{0}^{3}(6-2x)\,dx\right]$ $\int_{0}^{3}\sqrt{9-x^{2}}\,dx=\frac{\pi\cdot 3^{2}}{4}=\frac{9\pi}{4},\quad \int_{0}^{3}(6-2x)\,dx=9$ $A_s=\frac{1}{3}\left(2\cdot\frac{9\pi}{4}-9\right)=\frac{1}{3}\left(\frac{9\pi}{2}-9\right)=\frac{3\pi}{2}-3$ Total ellipse area $=\pi ab=6\pi$. Bigger portion area $=6\pi-\left(\frac{3\pi}{2}-3\right)=\frac{9\pi}{2}+3$ Final Area = $\frac{9\pi}{2}+3$ |