Practicing Success
The normal to the curve $2 x^2+y^2=12$ at the point (2, 2) cuts the curve again at |
$(-22 / 9,-2 / 9)$ $(-2,-2)$ $(22 / 9,2 / 9)$ none of these |
$(-22 / 9,-2 / 9)$ |
We have, $2 x^2+y^2=12$ .......(i) Differentiating w.r.t. $x$, we get $4 x+2 y \frac{d y}{d x}=0 \Rightarrow \frac{d y}{d x}=-\frac{2 x}{y} \Rightarrow\left(\frac{d y}{d x}\right)_{(2,2)}=-2$ The equation of the normal at $(2,2)$ is $y-2=\frac{1}{2}(x-2) \Rightarrow x-2 y+2=0$ ......(ii) Solving (i) and (ii), we obtain that the coordinates of their points of intersection are $(2,2)$ and $(-22 / 9,-2 / 9)$ Hence, the normal to the curve at $(2,2)$ cuts it again at $(-22 / 9,-2 / 9)$. |