=====atan2=====
Syntax:

<code>
    #include <cmath>
    double atan2( double y, double x );
</code>
The atan2() function computes the arc tangent of y/x, using the signs of the
arguments to compute the quadrant of the return value. The returned values are in the range [-pi, pi]. 
Note the order of the arguments passed to this function.

C++ also provides the following overloaded forms:
<code>
    #include <cmath>
    float atan2( float y, float x ); // same as atan2f() in C99
    long double atan2( long double y, long double x ); // same as atan2l() in C99
</code>

Related Topics: [[acos]], [[asin]], [[atan]], [[cos]], [[cosh]], [[sin]], [[sinh]], [[tan]], [[tanh]]