Four Fours/9/Solutions/3

Puzzle: Four Fours: $9$

Using exactly $4$ instances of the number $4$, the task is to write an expression for $9$, using whatever arithmetical operations you consider necessary.

Solution

$9 = \paren {\sqrt {\dfrac 4 {.\dot 4} } }^{\tfrac 4 {\sqrt 4} }$