tan
From cppreference.com
                    
                                        
                    
                    
                                                            
                    | Defined in header <math.h>
  | ||
| float       tanf( float arg ); | (since C99) | |
| double      tan( double arg ); | ||
| long double tanl( long double arg ); | (since C99) | |
Computes tangent of arg
[edit] Parameters
| arg | - | floating point value representing angle in radians | 
[edit] Return value
Tangent of arg.
Domain error occurs if arg is infinite. NAN is returned in that case.
[edit] See also
| computes sine (sin(x)) (function) | |
| computes cosine (cos(x)) (function) | |
| computes arc tangent (arctan(x)) (function) | |