Question

Ignore me, need latex editor

Answer 1

._.

Answer 2

\[\mu \in R, \sigma>0\]

Answer 3

\[f(x) = \frac{1}{\sqrt{2\pi}\sigma x}e^{-\frac{(lnx - \mu)^2}{2\sigma^2}}\]

Answer 4

\[f(x) = \frac{1}{\sqrt{2\pi} x}e^{-\frac{ln^2x}{2}}\]