Calculates the fractional and exponent parts of a floating-point
    value.

    Format

      #include  <math.h>

      double frexp  (double value, int *eptr);

      float frexpf  (float value, int *eptr);
                    (Integrity servers, Alpha)

      long double frexpl (long double value, int *eptr);
                          (Integrity servers, Alpha)