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Variants

    atan2, atan2f, atan2l

    From cppreference.com
    < c | numeric | math
     
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    Defined in header <math.h> 
    float       atan2f( float y, float x );
    		(1) (since C99) 
    double      atan2( double y, double x );
    		(2) 
    long double atan2l( long double y, long double x );
    		(3) (since C99) 
    _Decimal32  atan2d32( _Decimal32 y, _Decimal32 x );
    		(4) (since C23) 
    _Decimal64  atan2d64( _Decimal64 y, _Decimal64 x );
    		(5) (since C23) 
    _Decimal128 atan2d128( _Decimal128 y, _Decimal128 x );
    		(6) (since C23)
    Defined in header <tgmath.h> 
    #define atan2( y, x )
    		(7) (since C99)
    1-6) Computes the arc tangent of y / x using the signs of arguments to determine the correct quadrant.
    7) Type-generic macro: If any argument has type long double, (3) (atan2l) is called. Otherwise, if any argument has integer type or has type double, (2) (atan2) is called. Otherwise, (1) (atan2f) is called.

    The functions (4-6) are declared if and only if the implementation predefines __STDC_IEC_60559_DFP__ (i.e. the implementation supports decimal floating-point numbers).

    		(since C23)

    Parameters

    x, y - floating-point value

    Return value

    If no errors occur, the arc tangent of y / x (

    arctan(
    y
    x
    )

    ) in the range [-π ; +π] radians, is returned.

    Y argument
    Return value