The families of curves represented by the solution of the equation

$$\frac{dy}{dx}=\: – \left(\frac{x}{y} \right)^n$$

for $n=-1$ and $n= +1,$ respectively, are

1. Parabolas and Circles
2. Circles and Hyperbolas
3. Hyperbolas and Circles
4. Hyperbolas and Parabolas
in Others
edited