Solution
= Solution
<Euler's formula> gives $e^{iz}=e^{-y}(\cos x+i\sin x)$. Its <real part> and <imaginary part> are
$$
\boxed{e^{-y}\cos x,\qquad e^{-y}\sin x.}
$$
= Solution
<Euler's formula> gives $e^{iz}=e^{-y}(\cos x+i\sin x)$. Its <real part> and <imaginary part> are
$$
\boxed{e^{-y}\cos x,\qquad e^{-y}\sin x.}
$$