.1. Show that (coshx + sinhx)[to the power of] n = coshnx + sinhnx
This is trivial applying the definition of the hyperbolic functions
2. Determine the integral of tanhxdx
Take it from here now (if you know integrals of usual trigonometric functions this one won't surprise you).
3. Determine the integral of 4dx/(e to the x + e to the -x)squared
[colo=blue]Get some ideas from the above
PS How can i use the proper math symbols?!!