## Algebra and Trigonometry 10th Edition

The thumbtacks: $(±\sqrt 5,0)~ft$ The length of the string $=2\sqrt 5~ft$
The major axis is horizontal. The major axis is equal to the width of 6 feet: $2a=6$ $a=3$ The half of the minor axis is equal to the height of 2 feet: $b=2$ $a^2=b^2+c^2$ $c^2=a^2-b^2=3^2-2^2=5$ $c=\sqrt 5$ The thumbtacks must be placed at the foci. When major axis is horizontal: $(±c,0)=(±\sqrt 5,0)$ The length of the string is equal to $2c=2\sqrt 5$