Q. A hyperbola has its centre at the origin, passes through the point $(4,2)$ and has transverse axis of length $4$ along the x-axis. Then the eccentricity of the hyperbola is :
Solution:
$\frac{x^{2}}{a^{2}} - \frac{y^{2}}{b^{2}} = 1$
$ 2a =4 a=2$
$ \frac{x^{2}}{4} - \frac{y^{2}}{b^{2}} = 1 $
Passes through $(4,2)$
$ 4 - \frac{4}{b^{2}} = 1 \Rightarrow b^{2} = \frac{4}{3} \Rightarrow e = \frac{2}{\sqrt{3}} $
