Two curves $x^3-3xy^2+2=0$ and $3x^2y-y^3=2:$ |
Touch each other Cut at right angle Cut at an angle $\frac{\pi}{3}$ Cut at an angle $\frac{\pi}{4}$ |
Cut at right angle |
The correct answer is Option (2) → Cut at right angle $x^3-3xy^2+2=0$ and $3x^2y-y^3=2$ finding slopes for first $3x^2-3y^2-6xy\frac{dy}{dx}=0$ $x^2-y^2=2xy\frac{dy}{dx}$ $\frac{dy}{dx}=m=\frac{x^2-y^2}{2xy}$ for second $6xy+3x^2\frac{dy}{dx}-3y^2\frac{dy}{dx}=0$ so $\frac{dy}{dx}=n=-\frac{2xy}{x^2-y^2}$ so $m×n=-1$ both cut each other at right angle |