## Precalculus (6th Edition) Blitzer

Vertices: $(2,0)$ and $(-2,0)$ $c^2=a^2+b^2=4+1=5$ $c= \sqrt 5= 2.23$ Foci: $(2.23,0); (-2.23,0)$ This matches graphs (b) and (d). We choose graph (b) because the value under $x^2$ is larger than the value under $y^2$. Thus, the answer is graph (b).