Please help with these concepts, I would like to understand so I can do them on my own.

I honestly have no idea how to begin with these problems..

Write cosh^2(x) + sin^2x in terms of e^x, then write in terms of a hyperbolic trig function if possible.

Find the difference quotient at -1 for cosh(x)

Find tanh(3)

Develop/determine the relationship between tanh(x) and sinh(x)

Develop/determine the relationship between tanh(x) and sech(x)

Is sech^2(x) the difference quotient for tanh(x)? What is the difference quotient for tanh(x)? I've been trying to find out what it is in terms of a hyperbolic trigonometric function but I can't figure it out