Q114 / 180 · KCET 2011 · Mathematics
If $m$ and $n$ are degree and order of $\left(1+y_{1}^{2}\right)^{2 / 3}=y_{2}$, then the value of $\frac{m+n}{m-n}$ is
- A3
- B4
- Correct answerC5
- D2
Solution
Given differential equation is
$$
\begin{gathered}
\left(1+\left(\frac{d y}{d x}\right)^{2}\right)^{2 / 3}=\left(\frac{d^{2} y}{d x^{2}}\right) \\
\Rightarrow \quad\left(1+\left(\frac{d y}{d x}\right)^{2}\right)^{2}=\left(\frac{d^{2} y}{d x^{2}}\right)^{3} \\
\text { Now, } \quad \text { Order }=n=2 \\
\text { Degree }=m=3 \\
\text { Then, } \quad \frac{m+n}{m-n}=\frac{3+2}{3-2}=5
\end{gathered}
$$
Hence, the correct answer is option: 'C'.