Chapter 8 - Section 8.1 - Arc Length - 8.1 Exercises - Page 550: 42

$451$$meters$

$y$ $=$$211.49$ $-$$20.96$ $cosh$$0.03291765$$x$ $|x|$ $\leq$ $91.20$ $y'$ $=$ $-20.96$ $(0.03291765)$ $sinh$ $(0.03291765x)$ $\int_{-91.2}^{91.2}$ $\sqrt {1+(-20.96(0.03291765)sinh(0.03291765x))^{2}}$$dx$ $=$ $451.137$ $\approx$ $451$ $meters$