Solution
= Solution
{c}
The <hyperbolic sine> satisfies $\sinh z=(e^z-e^{-z})/2$. The <complex exponential function> is <entire>, and sums and compositions of <entire functions> are <entire>. Therefore
$$
\boxed{\sinh z\text{ is holomorphic on all of }\mathbb C,\qquad (\sinh z)'=\cosh z.}
$$