## Precalculus (6th Edition) Blitzer

Step 1. Using the figure given in the exercise, we have $a=25, b=20$ and the equation of the archway can be written as $\frac{x^2}{625}+\frac{y^2}{400}=1, y\geq0$ Step 2. The best position for the truck is to drive with one side on the middle line and the upper right corner will be $(10,14)$ Step 3. For $x=10$, the equation in step-1 becomes $\frac{10^2}{625}+\frac{y^2}{400}=1$, which gives $y\approx18.33\ ft$ Step 4. As $18.33 \gt 17$, we conclude that the truck can pass under the archway without going into the other lane.