atan2
From cppreference.com
                    
                                        
                    
                    
                                                            
                    |   Defined in header  
<math.h>
  | 
||
|   float       atan2f( float y, float x ); 
 | 
(since C99) | |
|   double      atan2( double y, double x ); 
 | 
(since C99) | |
|   long double atan2l( long double y, long double x ); 
 | 
(since C99) | |
Computes the inverse tangent of y/x using the signs of arguments to correctly determine quadrant. 
Contents | 
[edit] Parameters
| x, y | - | floating point value | 
[edit] Return value
Arc tangent of y/x in radians in the range of [-π; π] radians.
[edit] Example
| This section is incomplete Reason: no example  | 
[edit] See also
|   computes arc tangent (arctan(x))  (function)  | 
|
|    computes arc sine (arcsin(x))  (function)  | 
|
|   computes arc cosine (arccos(x))   (function)  | 
|
|    computes tangent (tan(x))  (function)  | 
|