- Home
- Standard 11
- Mathematics
10-2. Parabola, Ellipse, Hyperbola
easy
If $5{x^2} + \lambda {y^2} = 20$ represents a rectangular hyperbola, then $\lambda $ equals
A
$5$
B
$4$
C
$-5$
D
None of these
Solution
(c) Since the general equation of second degree represents a rectangular hyperbola,
if $\Delta \ne 0,\,\,{h^2} > ab$ and
coefficient of ${x^2} + $ coefficient of ${y^2} = 0$.
Therefore the given equation represents a rectangular hyperbola,
if $\lambda + 5 = 0$ $i.e.$, $\,\lambda = – 5$.
Standard 11
Mathematics