Solution (source code)

= Solution

The <complex exponential function> factorizes as $e^{x+iy}=e^xe^{iy}=e^x(\cos y+i\sin y)$. Hence
$$
\boxed{\operatorname{Re}(e^z)=e^x\cos y,\qquad \operatorname{Im}(e^z)=e^x\sin y.}
$$
The real exponential multiplies both components; it does not change the <argument>.