Solve x if ln(ln(x)) = 4

The logarithmic equation `ln(ln(x)) = 4` has to be solved
for x.

ln is used to denote natural logarithm which is
logarithm to the base e.

`ln(ln(x)) = 4` can be rewritten
as:

`log_e(log_ex) = 4`

If
`log_b a = c` , we can write `a = b^c`

This gives: `log_e x
= e^4`

Again doing the
same.

`x = e^(e^4)`

The root
of the equation `ln(ln(x)) = 4` is `x = e^(e^4)`