Call the graph of y = b - a cosh (x/a) an inverted catenary and imagine it to be an arch sitting on the x-axis. Show that if the width of this arch along the x-axis is 2a then each of the following is true.
(a) b = a cosh 1 ≈ 1.54308a.
(b) The height of the arch is approximately 0.54308a
(c) The height of an arch of width 48 is approximately 13.