Can you please help me solve these three problems. Thanks so much! :)

3. Hyperbolic trigonometric functions are defined as: sinh(x) := e - ex etez sinh x -, cosh(x) := tanh(x) := 2 2 cosh r Show the identity cosh (x) - sinh (x) = 1, by plugging in expressions for sinh x and cosh x into the identity. 4. Use the definitions of hyperbolic functions given above (in terms of exponentials) to show that dac [sinh(x)] = cosh(x), [cosh(x)] = sinh(x) 5. Compute d sinh '(x)