Four Fours/5/Solutions/2

Puzzle: Four Fours: $5$

Using exactly $4$ instances of the number $4$, the task is to write an expression for $5$, using whatever arithmetical operations you consider necessary.

Solution

$5 = \sqrt {\dfrac 4 {.\dot 4} } + \dfrac 4 {\sqrt 4}$

Sources

• 1980: Angela Dunn: Mathematical Bafflers (revised ed.) ... (previous) ... (next): $1$. Say it with Letters: Algebraic Amusements: Four Fours