A cable bangs between Iwo poles of equal hoolt and 22feet apart. Set up a coordinate systern where the poles are placed x = -11 x= 11 where X is measured in feet.
The height .(in feet) of cable position x is
h(x) = 7cosh(x/7),
where cosh(x) = ex + e-x)/ 2 is the hyperbdic cosine, which is an important function in physics and engineering.
Determine the length of the cable.