Answer
$$\cosh \left( {{e^x}} \right) + C$$
Work Step by Step
$$\eqalign{
& \int {{e^x}\sinh \left( {{e^x}} \right)} dx \cr
& {\text{substitute }}u = {e^x},{\text{ }}du = {e^x}dx \cr
& = \int {\sinh u} du \cr
& {\text{find the antiderivative using the theorem 6}}{\text{.8}}{\text{.3 }}\left( {{\text{see page 476}}} \right) \cr
& = \cosh u + C \cr
& {\text{write in terms of }}x \cr
& = \cosh \left( {{e^x}} \right) + C \cr} $$