AT&T UNIX™PC Unix System V Users Manual - tenox

EXP ( 3M ) EXP ( 3M )
NAME
exp, log, loglO, pow, sqrt - exponential, logarithm, power, square
root functions
SYNOPSIS
#include
double exp (x)
double x;
double log (x)
double x;
double loglO (x)
double x;
double pow (x, y)
double x, y;
double sqrt (x)
double x;
DESCRIPTION
Exp returns ex 0
Log returns the natural logarithm of x. The value of x must be
positive.
Logl 0 returns the logarithm base ten of x. The value of x must
be positive.
Pow returns xY 0 The values of x and y may not both be zero. If
x is non-positive, y must be an integer.
Sqrt returns the square root of x. The value of x may not be
negative.
DIAGNOSTICS
Exp returns HUGE when the correct value would overflow, and
sets errno to ERANGE.
Log and loglO return 0 and set errno to EDOM when x is nonpositive.
An error message is printed on the standard error output.
Pow returns 0 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 pow would
overflow, pow returns HUGE and sets errno to ERANGE.
Sqrt returns 0 and sets errno to EDOM when x is negative. A
message indicating DOMAIN error is printed on the standard error
output.
These error-handling procedures may be changed with the function
matherr(3M).
SEE ALSO
hypot(3M), matherr(3M), sinh(3M).
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