MCQ
Solution of the differential equation, $y\,dx - x\,dy + x{y^2}dx = 0$ can be
  • $2x + {x^2}y = \lambda y$
  • B
    $2y + {y^2}x = \lambda y$
  • C
    $2y - {y^2}x = \lambda y$
  • D
    None of these

Answer

Correct option: A.
$2x + {x^2}y = \lambda y$
a
(a) $\frac{{ydx - xdy}}{{{y^2}}} = - xdx$ ==> $d\left( {\frac{x}{y}} \right) = - xdx$

Integrating both side, we get $\frac{x}{y} = - \frac{{{x^2}}}{2} + c$

==> $2x + {x^2}y = 2cy$ ==> $2x + {x^2}y = \lambda y$ [$\lambda = 2c$]

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

If $\text{f(x)}=\sqrt{1-\sqrt{1-\text{x}^2}},$ then $f(x)$ is :
If $\theta $ be the angle between the vectors $a = 2i + 2j - k$ and $b = 6i - 3j + 2k$, then
The lines $\frac{1-x}{2}=\frac{y-1}{3}=\frac{z}{1}$ and $\frac{2 x-3}{2 p}=\frac{y}{-1}=\frac{z-4}{7}$ are perpendicular to each other for $p$ equal to :
$\int_{\,8}^{\,15} {\frac{{dx}}{{(x - 3)\sqrt {x + 1} }} = } $
Choose the correct answer from the given four options.
Two cards are drawn from a well shuffled deck of 52 playing cards with replacement. The probability, that both cards are queens, is:
Find the area of the triangle whose vertices are $(3,8),(-4,2)$ and $(5,1)$
The area of the triangle formed by the tangent to the hyperbola $xy = {a^2}$ and co-ordinate axes is
Statement $-1$ : The system of linear equations

$x + \left( {\sin \,\alpha } \right)y + \left( {\cos \,\alpha } \right)z = 0$

$x + \left( {\cos \,\alpha } \right)y + \left( {\sin \alpha } \right)z = 0$

$x - \left( {\sin \,\alpha } \right)y - \left( {\cos \alpha } \right)z = 0$

has a non-trivial solution for only one value of $\alpha $ lying in the interval $\left( {0\,,\,\frac{\pi }{2}} \right)$ 

Statement $-2$ : The equation in $\alpha $

$\left| {\begin{array}{*{20}{c}}
  {\cos {\mkern 1mu} \alpha }&{\sin {\mkern 1mu} \alpha }&{\cos {\mkern 1mu} \alpha } \\ 
  {\sin {\mkern 1mu} \alpha }&{\cos {\mkern 1mu} \alpha }&{\sin {\mkern 1mu} \alpha } \\ 
  {\cos {\mkern 1mu} \alpha }&{ - \sin {\mkern 1mu} \alpha }&{ - \cos {\mkern 1mu} \alpha } 
\end{array}} \right| = 0$

has only one solution lying in the interval $\left( {0\,,\,\frac{\pi }{2}} \right)$

$\int\text{e}^\text{x}(\frac{1-\text{x}}{1+\text{x}^2})^2\text{dx}$ is equal to:
The area bounded by the $x$-axis, the curve $y=f(x)$ and the lines $x=1, x=b$ is equal to $\sqrt{b^2+1}-\sqrt{2}$ for all $b>1$. Which of the following can be $f(x)$ ?