(BRAINLIEST QUESTION)

A cylindrical steel water pipe has a length of 12 feet and a radius of 1.5 feet. Which of these best represents the volume of this length of pipe?

A
57 ft^3

B
85 ft^3

C
113 ft^3

D
170 ft^3

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) = .