Practicing Success
The two curves $x^3-3 x y^2+15=0$ and $3 x^2 y-y^3+17=0$ : |
cut at right angles touch each other cut at an angle $\frac{\pi}{4}$ cut at angle $\frac{\pi}{3}$ |
cut at right angles |
Curves $x^3-3 x y^2+15=0$ ...(1) $3 x^2 y-y^3+17=0$ ...(2) Differentiating (1) wrt (x) $\frac{d}{d x}\left(x^3-3 y^2+15\right)=0$ $3 x^2-3 y^2-6 x y \frac{d y}{d x}=0$ So $6 x y \frac{d y}{d x}=-3\left(y^2-x^2\right)$ $\frac{d y}{d x}=\frac{-3\left(y^2-x^2\right)}{6 x y}=m_1$ Slope of curve 1 Differentiating (2) wrt (x) $\frac{d}{d x}\left(3 x^2 y-y^3+17\right)=0$ $6 x y+3 x^2 \frac{d y}{d x}-3 y^2 \frac{d y}{d x}=0$ $6 x y=\frac{d y}{d x}\left(3 y^2-3 x^2\right)$ $\frac{d y}{d x}=\frac{6 x y}{3\left(y^2-x^2\right)}=m_2$ slope of curve 2 $m_1 m_2=\frac{-3\left(y^2-x^2\right)}{6 x y} \frac{6 x y}{3\left(y^2-x^2\right)}=-1$ m1m2 = -1 |