And The Answer Is?

easy if you think about it,

so we get the equations:

cosh(x/a) = (40 + a)/a
sinh(x/a) = 40/a

We then use the hyperbolic identity and substitute the above results to get:

(40 + a)2/a2 – (40/a)2 = 1

But if you try to solve this there is a problem. This equation has no solution! So what is going on?

 think about this logically.

If the cable is 80 m, then half of it is 40 m. But notice 40 m from the top of a 50 m pole is already 10 m above the ground. The cable therefore is hanging directly downward! The cable has to be doubled back upon itself, and the two poles must be coincident and 0 m apart!

This part is actually a trick question: the two poles are a distance of 0 apart, no physics or equations were required to solve this one, just logical thinking, I said it was easy!