#include<stdio.h>
#include<math.h>
#define maxsize 100
#define eps 0.000001
int main(void)
{
    double a,b,t,x[maxsize],step,s0,s1,f();
    int i,n;

    printf("please input a= and b=\n");
    scanf("%lf  %lf",&a,&b);

    n=1;
    s0=(f(a)+f(b))*(b-a)/2;
    do
    {
            n=n+1;
            step=(b-a)/n;
        for(i=0;i<n;i++)
        {
        
            x[i]=a+i*step;
            s1=0;
                for(i=1;i<=n;i++)
               
                    s1+=(f(x[i+1])+f(x[i]))*step/2;
               
                    t=s0;
                    s0=s1;
               
                    
        
        }
        
    }
    while (fabs(s0-t)>eps);
    {
        printf("s0=%lf\n",s0);
        printf("此时步长为:%d",n);
        printf("\n");
    }
    return 0;
}
double f(double m)
{
    double y;
    y=sqrt(1+pow(m,2));
    return y;
}
   

   

一楼，你说的double f(double m)我试过了没用，也是一样的，我这个函数是用来：将积分区间分成N个等份，用梯形公式计算机积分f(1,0)sqrt(1+pow(x,2))的近似值

这是数值分析或者计算方法里面：数值积分与数值微分里面的题目，求积分的近似值