The problem can be easily solved remembering some properties of the hyperbolic functions. In fact is...
(1)
... so that is...
(2)
(3)
Kind regards
question:A telephone cable susbended between two poles 20 meters appart hangs in a curve with equation: where -10<=x<=10
how long is the cable?
work:using the formula
this gives me an impossible (beyond my level) integral to solve