cplxexp(3C++)

NAME
     exp, log, pow, sqrt - exponential, logarithm, power, square root
     functions for the C++ complex library

SYNOPSIS
     #include <complex.h>

     class complex {

     public:
               friend complex exp(complex);
               friend complex log(complex);
               friend complex pow(double, complex);
               friend complex pow(complex, int);
               friend complex pow(complex, double);
               friend complex pow(complex, complex);
               friend complex sqrt(complex);
     };

DESCRIPTION
     The following math functions are overloaded by the complex library,
     where:
      - x, y, and z are of type complex.

     z = exp(x)     Returns ex.

     z = log(x)     Returns the natural logarithm of x.

     z = pow(x, y)  Returns xy.

     z = sqrt(x)    Returns the square root of x, contained in the first or
                    fourth quadrants of the complex plane.

SEE ALSO
     complex(3C++), cartpol(3C++), cplxerr(3C++), cplxops(3C++), and
     cplxtrig(3C++).

DIAGNOSTICS
     exp returns (0, 0) when the real part of x is so small, or the imaginary
     part is so large, as to cause overflow.  When the real part is large
     enough to cause overflow, exp returns (HUGE, HUGE) if the cosine and sine
     of the imaginary part of x are positive, (HUGE, -HUGE) if the cosine is
     positive and the sine is not, (-HUGE, HUGE) if the sine is positive and
     the cosine is not, and (-HUGE, -HUGE) if neither sine nor cosine is
     positive.  In all these cases, errno is set to ERANGE.

     log returns (-HUGE, 0) and sets errno to EDOM when x is (0, 0).  A
     message indicating SING error is printed on the standard error output.

     These error-handling procedures may be changed with the function
     complex_error (cplxerr(3C++)).