=====atan=====
Syntax:

<code>
    #include <cmath>
    double atan( double arg );
</code>
The function atan() returns the arc tangent of arg, which will be in the range
[-pi/2, +pi/2].

C++ also provides the following overloaded forms:
<code>
    #include <cmath>
    float atan( float arg ); // same as atanf() in C99
    long double atan( long double arg ); // same as atanl() in C99
</code>

Related Topics: [[acos]], [[asin]], [[atan2]], [[cos]], [[cosh]], [[sin]], [[sinh]], [[tan]], [[tanh]]