If two points $P$ and $Q$ on the hyperbola $\frac{{{x^2}}}{{{a^2}}} - \frac{{{y^2}}}{{{b^2}}} = 1$ whose centre is $C$, are such that $CP$ is perpendicular to $CQ, ( a < b )$ , then value of, $\frac{1}{{{{(CP)}^2}}} + \frac{1}{{{{(CQ)}^2}}} = $
$\frac {1}{ab}$
$\frac{1}{{{a^2}}} - \frac{1}{{{b^2}}}$
$\frac{1}{{{a^2}}} + \frac{1}{{{b^2}}}$
$\frac{1}{{{a^2} + {b^2}}}$
The tangent to the hyperbola $xy = c^2$ at the point $P$ intersects the $x-$ axis at $T$ and the $y-$ axis at $T'$. The normal to the hyperbola at $P$ intersects the $ x-$ axis at $N$ and the $y-$ axis at $N'$. The areas of the triangles $PNT$ and $PN'T' $ are $ \Delta$ and $ \Delta ' $ respectively, then $\frac{1}{\Delta }\,\, + \,\,\frac{1}{{\Delta '}}\,$ is
The equation of the hyperbola whose directrix is $x + 2y = 1$, focus $(2, 1)$ and eccentricity $2$ will be
The condition that the straight line $lx + my = n$ may be a normal to the hyperbola ${b^2}{x^2} - {a^2}{y^2} = {a^2}{b^2}$ is given by
The distance between the directrices of a rectangular hyperbola is $10$ units, then distance between its foci is
Let $H$ be the hyperbola, whose foci are $(1 \pm \sqrt{2}, 0)$ and eccentricity is $\sqrt{2}$. Then the length of its latus rectum is