The line $lx + my - n = 0$ will be tangent to the ellipse $\frac{{{x^2}}}{{{a^2}}} + \frac{{{y^2}}}{{{b^2}}} = 1$, if
${a^2}{l^2} + {b^2}{m^2} = {n^2}$
$a{l^2} + b{m^2} = {n^2}$
${a^2}l + {b^2}m = n$
None of these
In an ellipse the distance between its foci is $6$ and its minor axis is $8$. Then its eccentricity is
Minimum area of the triangle by any tangent to the ellipse $\frac{{{x^2}}}{{{a^2}}} + \frac{{{y^2}}}{{{b^2}}} = 1$ with the coordinate axes is
Let $F_1$ & $F_2$ be the foci of an ellipse $\frac{{{x^2}}}{4} + \frac{{{y^2}}}{9} = 1$ such that a ray from $F_1$ strikes the elliptical mirror at the point $P$ and get reflected. Then equation of angle bisector of the angle between incident ray and reflected ray can be
The sum of focal distances of any point on the ellipse with major and minor axes as $2a$ and $2b$ respectively, is equal to
If the co-ordinates of two points $A$ and $B$ are $(\sqrt{7}, 0)$ and $(-\sqrt{7}, 0)$ respectively and $P$ is any point on the conic, $9 x^{2}+16 y^{2}=144,$ then $PA + PB$ is equal to