acos [C++ Reference]
Keywords: c,math,acos
Date: 2009-03-19T23:41:16-0700

## acos

Syntax:

        #include <cmath>
        double acos( double arg );

The acos() function returns the arc cosine of arg, which will be in the range [0, pi]. arg should be between -1 and 1. If arg is outside this range, acos() returns NAN and raises a floating-point exception.

C++ also provides the following overloaded forms:

        #include <cmath>
        float acos( float arg ); // same as acosf() in C99
        long double acos( long double arg ); // same as acosl() in C99

Related Topics: asin, atan, atan2, cos, cosh, sin, sinh, tan, tanh