Q90 / 160 · AP EAMCET 2024 (22 May Shift 2) · Mathematics
Parametric equations of the circle $2 x^2+2 y^2=9$ are
- A$x=\frac{3}{2} \cos \theta, y=\frac{3}{2} \sin \theta$
- B$x=\frac{3}{\sqrt{2}} \cos \theta, y=3 \sin \theta$
- Correct answerC$x=\frac{3}{\sqrt{2}} \sin \theta, y=\frac{3}{\sqrt{2}} \cos \theta$
- D$x=3 \sin \theta, y=\frac{3}{2} \cos \theta$
Solution
Given circle: $2 x^2+2 y^2=9 \Rightarrow x^2+y^2=\frac{9}{2}$ $\Rightarrow$ Centre is $(0,0)$ and $r=\frac{3}{\sqrt{2}}$
Parametric equation is given by
$\begin{aligned}
& x=r \cos \theta, y=r \sin \theta \\
& \therefore x=\frac{3}{\sqrt{2}} \cos \theta, y=\frac{3}{\sqrt{2}} \sin \theta
\end{aligned}$
Hence, the correct answer is option: 'C'.