## Precalculus (6th Edition) Blitzer

Step 1. Based on the given conditions, we have $a=50, b=30$ and the equation of the ellipse can be written as $\frac{x^2}{50^2}+\frac{y^2}{30^2}=1$ or $\frac{x^2}{2500}+\frac{y^2}{900}=1, y\geq0$ Step 2. Using the above results, we have $c=\sqrt {a^2-b^2}=\sqrt {1600}=40\ ft$. Thus they should stand, in opposite, 40 feet away from the center.