William L.
Ellis
02-23-15
E-portfolio test assignment
35. In Exercise 26 in Section 2.3, we stated that the cable of a suspension bridge
formed a parabola but that a free hanging cable did not. A free hanging cable forms
a catenary and its basic shape is given by
y=
1
2
( e
). Use your
calculator to graph this function. What are its domain and range? What is its end
behavior? Is it invertible? How do you think it is related to the function given in
Exercise 47 in Section 6.3 and the one given in the answer to Exercise 38 in Section
6.4? When flipped upside down, the catenary makes an arch. The Gateway Arch in
St. Louis, Missouri has the shape
y = 757.7
127.7
x
(e
)
2
127.7 +
127.7
where x and y are measured in feet and 315 x 315. Find the highest point on
the arch.