第 23 題 - 解答

#include <stdio.h>

#include <math.h>

double fun(double,double);

int main()

{

   double x; 

   printf("請輸入x(x>0)值："); 

   scanf("%lf",&x); 

   printf("h=10^-1 , 微分值=%f\n",fun(x,pow(10,-1))); 

   printf("h=10^-2 , 微分值=%f\n",fun(x,pow(10,-2)));

   printf("h=10^-3 , 微分值=%f\n",fun(x,pow(10,-3)));

   return 0;

}

double fun(double x, double h)

{

   return (log(x+h)-log(x))/h;

}

#include <stdio.h>

#include <math.h>

double fun(double,double);

int main()

{

   double x; 

   scanf("%lf",&x); 

   printf("%f\n",fun(x,pow(10,-1))); 

   printf("%f\n",fun(x,pow(10,-2)));

   printf("%f\n",fun(x,pow(10,-3)));

   return 0;

}

double fun(double x, double h)

{

   return (log(x+h)-log(x))/h;

}