Stewart – Calculus ET 8e Chapter 10 Form E
____ 15. In the LORAN (LOng RAnge Navigation) radio navigation system, two radio stations located at A
and B transmit simultaneous signals to a ship or an aircraft located at P. The onboard computer
converts the time difference in receiving these signals into a distance difference , and this,
according to the definition of a hyperbola, locates the ship or aircraft on one branch of a hyperbola
(see the figure). Suppose that station B is located L = mi due east of station A on a coastline. A
ship received the signal from B microseconds (µs) before it received the signal from A.
Assuming that radio signals travel at a speed of ft /µs and if the ship is due north of B, how
far off the coastline is the ship? Round your answer to the nearest mile. Select the correct answer.
a. miles
b. miles
c. miles
d. miles
e. miles
16. Find an equation of the ellipse that satisfies the given conditions.
Foci: (0, ± 1), vertices (0, ± 6)
17. The orbit of Hale-Bopp comet, discovered in 1995, is an ellipse with eccentricity and one
focus at the Sun. The length of its major axis is AU. [An astronomical unit (AU) is the
mean distance between Earth and the Sun, about 93 million miles.] Find the maximum distance
from the comet to the Sun. (The perihelion distance from a planet to the Sun is and the
aphelion distance is .) Find the answer in AU and round to the nearest hundredth.
18. Write a polar equation of the conic that has a focus at the origin, eccentricity
7
2
, and directrix
. Identify the conic.