#include <cmath>
#include <limits>
#include <iostream>

int main() {
  std::cout << std::fixed;
  std::cout << "sqrt(0.0)  = " << std::sqrt(0.0) << std::endl;
  std::cout << "sqrt(0.5)  = " << std::sqrt(0.5) << std::endl;
  std::cout << "sqrt(1.0)  = " << std::sqrt(1.0) << std::endl;
  std::cout << "sqrt(2.0)  = " << std::sqrt(2.0) << std::endl;
  std::cout << "sqrt(4.0)  = " << std::sqrt(4.0) << std::endl;
  std::cout << "sqrt(+∞)   = "
            << std::sqrt(std::numeric_limits<double>::infinity())
            << std::endl;
  std::cout << "sqrt(-0.0) = " << std::sqrt(-0.0) << std::endl;
  std::cout << "sqrt(-1.0) = " << std::sqrt(-1.0) << std::endl;
}