Browse Questions

General solution of differential equation : $x dy +y dx=0$

$(a)\;(\frac{x}{y})+c=0 \\ (b)\;xy=c \\ (c)\;x^2+y^2=c \\ (d)\;x^2-y^2=c$

$xdy=-ydx$
$\large\frac{dy}{y} =\frac{-dx}{x}$
$\log y= -\log x +c_1$
$\log (xy) =c_1$
$xy=c$
Hence b is the correct answer.