Question

Solution of the differential equation $xdy - ydx = 0$ represents a

• A. parabola
• B. circle
• C. hyperbola
• D. straight line

Answer 1

Answer: (D)

straight line

Answer 2

$x \cdot d y-y \cdot d x=0$
$\Rightarrow x d y=y d x$
$\frac{d y}{y}=\frac{d x}{x}$
$\Rightarrow \log y=\log x+\log c$
$\Rightarrow \log y=\log c x$
$\Rightarrow y=x c$