exp(3M)                          DG/UX 5.4.2                         exp(3M)


NAME
       exp, expf, cbrt, log, logf, log10, log10f, pow, powf, sqrt, sqrtf -
       exponential, logarithm, power, square root functions

SYNOPSIS
       cc [flag ...] file ...  -lm [library ...]

       #include <math.h>

       double exp (double x);

       float expf (float x);

       double cbrt (double x);

       double log (double x);

       float logf (float x);

       double log10 (double x);

       float log10f (float x);

       double pow (double x, double y);

       float powf (float x, float y);

       double sqrt (double x);

       float sqrtf (float x);

DESCRIPTION
       exp and expf return ex.

       cbrt returns the cube root of x.

       log and logf return the natural logarithm of x.  The value of x must
       be positive.

       log10 and log10f return the base ten logarithm of x.  The value of x
       must be positive.

       pow and powf return xy.  If x is 0, y must be positive.  If x is
       negative, y must be an integer.

       sqrt and sqrtf return the non-negative square root of x.  The value
       of x may not be negative.

DIAGNOSTICS
       exp and expf return HUGE when the correct value would overflow, or 0
       when the correct value would underflow, and set errno to ERANGE.

       log, logf, log10, and log10f return -HUGE and set errno to EDOM when
       x is non-positive.  A message indicating DOMAIN error is printed on



Licensed material--property of copyright holder(s)                         1

exp(3M)                          DG/UX 5.4.2                         exp(3M)


       standard error.

       pow and powf return 0 and set errno to EDOM when x is 0 and y is non-
       positive, or when x is negative and y is not an integer.  In these
       cases, a message indicating DOMAIN error is printed on standard
       error.  When the correct value for pow or powf would overflow or
       underflow, these functions return ±HUGE or 0, respectively, and set
       errno to ERANGE.

       sqrt and sqrtf return 0 and set errno to EDOM when x is negative.  A
       message indicating DOMAIN error is printed on standard error.

       Except when the -Xc compilation option is used, these error-handling
       procedures may be changed with the function matherr.  When the -Xa or
       -Xc compilation options are used, HUGEVAL is returned instead of
       HUGE and no error messages are printed.  In these compilation modes,
       pow and powf return 1, with no error, when both x and y are 0; when x
       is 0 and y is negative, they return -HUGEVAL and set errno to EDOM.
       Under -Xc, log and logf return -HUGEVAL and set errno to ERANGE when
       x is 0.  Under -Xc, sqrt and sqrtf return NaN when x is negative.

SEE ALSO
       hypot(3M), matherr(3M), sinh(3M).


































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