The mathematic significes of the st.louis arch?

i got to do a report of the arch as a catenary curve and i need all the informations that i can getThe mathematic significes of the st.louis arch?
The equation for the arch is:



y = 693.8597 - 68.7672 COSH(0.0100333 x) feetThe mathematic significes of the st.louis arch?
catenary is an interesting curve, known since ancient greece at least; it is called so because it describes the least energy configuration of a homogeneous wire (or chain; italian "catena") fixed by two points at equal heights, under the gravitation field.

It's used in bridge constructions because of its least energy properties (even though it is often approximated by parabolas which are simpler to calculate).