#include <iostream> #include <iomanip> #define _USE_MATH_DEFINES #include<cmath> using namespace std; long double pi = 3.141592653589793; int main() { double x, y, z, w; cout << std::setprecision(16) << M_PI << endl << pi << endl << sin(M_PI/2) << endl; cout << hypot(3,4) << endl << pow(4,0.5) << endl; }