pow

Description

The pow functions compute x raised to the power of y, i.e.

#include <math.h>
#include <stdio.h>
int main(void)
{
  for(int i = 1; i < 5; i++)
     printf("pow(3.2, %d) = %lf\n", i, pow(3.2, i));  
  return 0;
}

pow(3.2, 1) = 3.200000
pow(3.2, 2) = 10.240000
pow(3.2, 3) = 32.768000
pow(3.2, 4) = 104.857600

Special Values

pow ( ±0, y ) returns ±∞ and raises the divide-by-zero floating-point exception for y an odd integer.

pow ( ±0, y ) returns +∞ and raises the divide-by-zero floating-point exception for y < 0 and not an odd integer.

pow ( ±0, y ) returns ±0 for y an odd integer > 0.

pow ( ±0, y ) returns +0 for y > 0 and not an odd integer.

pow ( -1, ±∞ ) returns 1.

pow ( 1, y ) returns 1 for any y, even a NaN.

pow ( x, ±0 ) returns 1 for any x, even a NaN.

pow ( x, y ) returns a NaN and raises the invalid floating-point exception for finite x < 0 and finite non-integer y.

pow ( x, -∞ ) returns +∞ for |x| < 1.

pow ( x, -∞ ) returns +0 for |x| > 1.

pow ( x, +∞ ) returns +0 for |x| < 1.

pow ( x, +∞ ) returns +∞ for |x| > 1.

pow ( -∞, y ) returns -0 for y an odd integer < 0.

pow ( -∞, y ) returns +0 for y < 0 and not an odd integer.

pow ( -∞, y ) returns -∞ for y an odd integer > 0.

pow ( -∞, y ) returns +∞ for y > 0 and not an odd integer.

pow ( +∞, y ) returns +0 for y < 0.

pow ( +∞, y ) returns +∞ for y > 0.

A domain error occurs if x is finite and negative and y is finite and not an integer.

A domain error can occur if x is 0 and y less than or equal to 0.

See Also

reference:exp, reference:log

Standards

The pow function conforms to ISO/IEC 9899:1999(E).