Q230 / 270 · NDA 2022 (Phase 1) · Mathematics
What does the equation $x \frac{d y}{d x}-2 y=0$ represent?
- AA family of straight lines
- BA family of circles
- Correct answerCA family of parabolas
- DA family of ellipses
Solution
$\begin{aligned} & x \frac{d y}{d x}-2 y=0 \\ & x \frac{d y}{d x}=2 y\end{aligned}$
$\int \frac{1}{\mathrm{y}} \mathrm{dy}=2 \int \frac{1}{\mathrm{x}} \mathrm{dx}$
$\begin{aligned} & \ell \text { ny }=2 \ln x+\ell \mathrm{nc} \\ & \ell \text { ny }=\ell \mathrm{nx}^2+\ell \mathrm{nc} \\ & \ell \mathrm{n} y=\ell \mathrm{n}\left(\mathrm{cx}^2\right) \\ & \mathrm{y}=\mathrm{cx}^2\end{aligned}$
It represent the equation of parabolas.
Hence, the correct answer is option: 'C'.