User:Pettythug

$\varepsilon = \sqrt{1 - \frac{b^2}{a^2}}$

$\frac{x^{2}}{a^{2}} + \frac{y^{2}}{b^{2}} = 1$

$\frac{x^{2}}{9} + \frac{y^{2}}{4} = 1$

$\sqrt{1 - \frac{4}{9}}$

$\sqrt{\frac{5}{9}}$

$\frac{\sqrt{5}}{3}$

$\ + or - \frac{a}{e}$

$\ + or - \frac{3}{\frac{\sqrt{5}}{3}}$

$\ + or - \frac{9}{\sqrt{5}}$

$\sqrt{(\frac{3}{2}\sqrt{3} - \sqrt{5})^2 + 1^2}$

$\frac{\sqrt{5}}{3}.(\frac{9}{\sqrt{5}} - \frac{3}{2}\sqrt{3})$

$\left(\sqrt{5},0\right)$

$\left(-\sqrt{5},0\right)$

$\left(\frac{3}{2}\sqrt{3},1\right)$