=====cos=====
Syntax:

<code>
    #include <cmath>
    double cos( double arg );
</code>
The cos() function returns the cosine of arg, where arg is expressed in
radians. The return value of cos() is in the range [-1,1]. If arg is infinite,
cos() will return NAN and raise a floating-point exception.

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

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