EXP(3M) — HP-UX

NAME

exp, log, log10, pow, sqrt − exponential, logarithm, power, square root functions

SYNOPSIS

#include <math.h>

double exp (x)
double x;

double log (x)
double x;

double log10 (x)
double x;

double pow (x, y)
double x, y;

double sqrt (x)
double x;

DESCRIPTION

Exp returns ex.

Log returns the natural logarithm of x. The value of x must be positive.

Log10 returns the logarithm base ten of x. The value of x must be positive.

Pow returns xy. If x is zero, y must be positive. If x is negative, y must be an integer.

Sqrt returns the non-negative square root of x. The value of x may not be negative.

HARDWARE DEPENDENCIES

Series 200, 300, 500:
The algorithms used are those from HP 9000 BASIC.

ERRORS

Exp returns HUGE when the correct value would overflow, or 0 when the correct value would underflow, and sets errno to ERANGE.

Log and log10 return −HUGE and set errno to EDOM when x is non-positive. A message indicating DOMAIN error (or SING error when x is 0) is printed on the standard error output.

Pow returns 0 and sets 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 the standard error output. When the correct value for pow would overflow or underflow, pow returns ±HUGE or 0 respectively, 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).

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