Compute the square root of a non-negative number. Returns the decimal result, whether the input is a perfect square, and a simplified radical form (e.g. '√12' simplifies to '2√3'). For integer inputs, factors are extracted from under the radical sign. Useful for geometry (diagonal/hypotenuse calculations), statistics (standard deviation from variance), signal processing (RMS values), and general algebra. Chain with pythagorean_theorem for triangle side calculations.