#include <cmath>
#include <iostream>
using namespace std;
const double PI=3.14159;//常數宣告
double degrees_to_radian(double deg)
{
return deg * PI / 180.0;
}
int main()
{
cout << "sin(45.0) = " << sin(degrees_to_radian(45)) << endl;
cout << "cos(45.0) = " << cos(degrees_to_radian(45)) << endl;
}