Differential Equations

$y-x=c x^2$

$\tan ^{-1}\left(\frac{y}{x}\right)=\log \left(c x \sqrt{x^2+y^2}\right)$

$x+y=c x^2$

$\tan ^{-1}\left(\frac{y}{x}\right)=\log \left(c \sqrt{x^2+y^2}\right)$