An electric cable strung between supporting posts, takes the form of the following curve, which is called a
catenary, and which has the following relationship:
𝑦 = a cosh (𝑑/2a)
a = minimum height above the ground of the cable
d = distance between the supporting posts
(i) If the height of the posts is 10 m and the minimum height of the cable above the ground is
8 m, determine the distance between the posts.
(ii) Determine the length of the cable s, between the posts in (i) above, given by the following
equation:
𝑠 = 2a sinh ( 𝑑/2a)