## Algebra and Trigonometry 10th Edition

Vertices: $(0,±3)$ Eccentricity: $e=\frac{2}{3}$
$9x^2+5y^2=45$ $\frac{x^2}{5}+\frac{y^2}{9}=1$ $\frac{x^2}{(\sqrt 5)^2}+\frac{y^2}{3^2}=1$ The major axis is vertical. Standard form when major axis is vertical: $\frac{x^2}{b^2}+\frac{y^2}{a^2}=1$ So: $a=3$ and $b=\sqrt 5$ $a^2=b^2+c^2$ $c^2=a^2-b^2=9-5=4$ $c=2$ $e=\frac{c}{a}=\frac{2}{3}$ Vertices when major axis is horizontal: $(0,±a)=(0,±3)$