atan2(x,y)函数详解

float atan2(float y, float x);
double atan2(double y, double x);
long double atan2(long double y, long double x);
Promoted atan2(Arithmetic1 y, Arithmetic x );

#include <iostream>  
#include<math.h>  
using namespace std;  
int main()  
{  
    int x=0;  
    int y=0;  
    cout<<"Value of tan(y/x) is : "<<tan(y/x)<<'\n';  
    std::cout << "Value of tan-1(y/x) is : " <<atan2(y,x)<< std::endl;  
    return 0;  
}  

#include <iostream>  
#include<math.h>  
using namespace std;  
int main()  
{  
    int x=6;  
    float y=7.8;  
    cout<<"Value of tan(y/x) is : "<<tan(y/x)<<'\n';  
    std::cout << "Value of tan-1(y/x) is : " <<atan2(y,x)<< std::endl;  
    return 0;  
}