Hey guys, I'm in System Dynamics and have been given a fairly fundemental problem to work on.

It states: $\displaystyle x(t) = Acosh(pt) + Bsinh(pt)$ can also be written $\displaystyle x(t) = Ce^{pt} + De^{-pt}$. It then instructs me to derive equations for C and D in terms of A and B. I know this is pretty fundemental, I also know that $\displaystyle e^{pt} = cosh(pt) + sinh(pt)$, and $\displaystyle e^{-pt} = cosh(pt) - sinh(pt)$ but I do not want to confuse deriving an equation with substitution.

I'm not looking for an answer or anything like that, I just need someone or several people to put me on the right path. I'm not quite sure where to start. Thank you.