Show that there exists some $g(y/x) = \frac{-M(x,y)}{N(x,y)} $

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Given: $M(x,y)dx + N(x,y)dy = 0$

Show that there exists some $g(y/x) = \frac{dy}{dx} = \frac{-M(x,y)}{N(x,y)}$


Is my way of doing this problem correct?


FIRST: Solving for $\frac{dy}{dx}$ in $M(x,y)dx + N(x,y)dy = 0$ yields: $\frac{dy}{dx} = \frac{-M(x,y)}{N(x,y)}$

SECOND: Let $v(y/x) = \frac{y}{x}$

-->$y=v(y/x)x$

-->$\frac{dy}{dx} = v^{'}(y/x)*\frac{-y}{x^{2}}*x + v(y/x)$

-->$\frac{dy}{dx} = v(y/x) - \frac{y}{x}*v^{'}(y/x)$

THIRD: Therefore, $\frac{dy}{dx} = g(y/x) = v(y/x) - \frac{y}{x}*v^{'}(y/x)=\frac{-M(x,y)}{N(x,y)}$

-->$g(y/x) = v(y/x) - \frac{y}{x}*v^{'}(y/x)$