exp(3m)exp(3m)Name
exp, expm1, log, log10, log1p, pow, sqrt - exponential, logarithm,
power, square root
Syntax
#include <math.h>
double exp(x)
double x;
double expm1(x)
double x;
double log(x)
double x;
double log10(x)
double x;
double log1p(x)
double x;
double pow(x,y)
double x,y;
double sqrt(x)
double x;
Description
The function returns the exponential function of x.
The function returns exp(x)-1 accurately even for tiny x.
The function returns the natural logarithm of x; returns the base 10
logarithm.
The function returns log(1+x) accurately even for tiny x.
The function returns x raised to the y power.
The function returns the square root of x.
Return Values
The function returns HUGE_VAL and sets errno to ERANGE when the correct
value would overflow. When the correct value would underflow it
returns zero and errno is set to ERANGE.
The function returns HUGE_VAL and sets errno to ERANGE when the correct
value would overflow. When the correct value would underflow it
returns -1.
The and functions return -HUGE_VAL and set errno to EDOM when x is less
than or equal to zero. When the correct value would overflow flow they
return -HUGE_VAL and errno is set to ERANGE.
The function returns -HUGE_VAL and sets errno to EDOM when x is less
than or equal to -1. When the correct value would overflow flow it
returns -HUGE_VAL and errno is set to ERANGE.
The function has many special cases. When x and y are both zero it
returns 1.0. When x is negative and y is not an integer value it
returns zero and errno is set to EDOM. When x is zero and y is nega‐
tive it returns -HUGE_VAL and errno is set to EDOM. When the correct
value would overflow HUGE_VAL is returned and errno is set to ERANGE.
When the correct value would underflow zero is returned and errno is
set to ERANGE.
The function returns zero and sets errno to EDOM when x is negative.
Environment
When your program is compiled using the System V environment, returns
HUGE when the correct value would overflow, and sets errno to ERANGE;
returns zero when the correct value would underflow, and sets errno to
ERANGE.
The and functions return HUGE and set errno to EDOM when x is nonposi‐
tive. An error message is printed on the standard error output.
The function returns zero and sets errno to EDOM when x is non-positive
and y is not an integer, or when x and y are both zero. In these
cases, a message indicating DOMAIN error is printed on the standard
error output. When the correct value for would overflow, returns HUGE
and sets errno to ERANGE.
The function returns zero and sets errno to EDOM when x is negative. A
message indicating DOMAIN error is printed on the standard error out‐
put.
These error-handling procedures may be changed with the function
DOMAIN error is only printed in the System V environment.
See Alsohypot(3m), intro(3m), sinh(3m)
VAX exp(3m)
