NAME

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

SYNOPSIS

cc [flag ...] file ... −lm [library ...]

cc −O −Ksd [flag ...] file ... −J sfm [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. 

SEE ALSO

hypot(3M), matherr(3M), sinh(3M)

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 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 the standard error output. 

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, HUGE_VAL is returned instead of HUGE and no error messages are printed.  In the −Xc compilation mode, pow and powf return 1,  setting errno to EDOM, when both x and y are 0; in the −Xa compilation mode, pow and powf return 0, setting errno to EDOM; when x is 0 and y is negative, they return −HUGE_VAL and set errno to EDOM.  Under −Xc, log and logf return −HUGE_VAL and set errno to ERANGE when x is 0.  Under −Xc, sqrt and sqrtf return NaN when x is negative. 

  —  Math Libraries