[Chapter 3] 3.2.157 sqrt

3.2.157 sqrt

sqrt EXPR
sqrt

This function returns the square root of EXPR. If EXPR is omitted, it returns the square root of $_. For other roots such as cube roots, you can use the ** operator to raise something to a fractional power.[8]

[8] Don't try either of these approaches with negative numbers, as that poses a slightly more complex problem.