I have done this by using Laplace equation as I assumed $\log(|f(z)|)$ to be some variable '$w$' and proved the (second derivative of '$w$' with respect to $u$) +(second derivative of '$w$' with respect to $v$) is zero. Was it correct.

I have done this by using Laplace equation as I assumed $\log(|f(z)|)$ to be some variable '$w$' and proved the (second derivative of '$w$' with respect to $u$) +(second derivative of '$w$' with respect to $v$) is zero. Was it correct.

If $f$ is holomorphic on some open set $D$ in $\mathbb C$ and if $f$ has no zeroes in $D$, then $\log(|f|)$ is harmonic in $D$.
Show your proof, then we will see whether your proof is correct.
$f(z)=e^z$ is analytic and $\log|f|=x\neq0$.