C library function - log()

Description

The C library function double log(double x) returns the natural logarithm (base-e logarithm) of x.

Declaration

Following is the declaration for log() function.

double log(double x)

Parameters

• x -- This is the floating point value.

Return Value

This function returns natural logarithm of x.

Example

The following example shows the usage of log() function.

#include <stdio.h>
#include <math.h>

int main ()
{
   double x, ret;
   x = 2.7;

   /* finding log(2.7) */
   ret = log(x);
   printf("log(%lf) = %lf", x, ret);
   
   return(0);
}

Let us compile and run the above program, this will produce the following result:

log(2.700000) = 0.993252