Programming Perl, 4th Edition

sqrt

sqrt EXPR
sqrt

This function returns the square root of EXPR. For other roots such as cube roots, you can use the ** operator to raise something to a fractional power. Don’t try either of these approaches with negative numbers, as that poses a slightly more complex problem (and raises an exception). But there’s a standard module to take care of even that:

use Math::Complex;
print sqrt(–2);    # prints 1.4142135623731i