The volume of a cone is 88 PI cubic feet. Its height is 6 feet. Singha is finding the diameter of the base of the cone. Her work is shown below.

Prove (a) cosh2(x) − sinh2(x) = 1 and (b) 1 − tanh 2(x) = sech 2(x). solution (a) cosh2(x) − sinh2(x) = ex + e−x 2 2 − 2 = e2x + 2 + e−2x 4 − = 4 = . (b) we start with the identity proved in part (a): cosh2(x) − sinh2(x) = 1. if we divide both sides by cosh2(x), we get 1 − sinh2(x) cosh2(x) = 1 or 1 − tanh 2(x) = .

100 points? me its important ‼️‼️‼️‼️‼️‼️‼️‼️‼️‼️‼️

Collin did the work to see if 10 is a solution to the equation r/4=2.4