Example 4: Solve the following hyperbolic equation using the hyperbolic identity cosh 2x = 2sinh x + 1; cosh 2x - 13 sinh x = -19. Exercises 1: a) Use the definition of hyperbolic functions to prove that e cosh'x + sinh2x = cosh(2x). b) Solve 2 sinh 2x - cosh 2x = 5 by using the definition of the hyperbolic functions. (Answer: x=1.1687 , no solution) c) Solve the following hyperbolic equation using the hyperbolic identity cosh2x - sinh x = 1; cosh x - 2 sinh x - 4 = 0. (Answer: x = -0.8814, x = 1.8184)