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 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, HUGE_VAL 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 -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.