This has the function of $1280(\frac{e^{\frac{x}{1326} }+ e^{-\frac{x}{1326}}}{2}-1). -640\leq x\leq 640$
Across this bridge, it has 84 pairs of equally spaced vertical suspenders.
I have attempted to use the Riemann sum such as $\sum_{i=1}^{42}(\cosh(\frac{\frac{320i}{21}}{1326})-1 )(\frac{320}{21})$ giving $33346.25$
and also $\sum_{i=1}^{84}(\cosh(\frac{\frac{320i}{21}}{1326})-1 )(\frac{320}{21})$ giving $271499.70$
Is this the correct way of doing this or has something wrong been done?