#include
#include
#define maxsize 100
#define eps 0.000001
int main(void)
{
    double a,b,t,x[maxsize],step,s0,s1;
    double f(double m);
    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++;
        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;
}
    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 。把不规则的图形换成梯形，然后将梯形分割成若干个小梯形，使小梯形相加，最后近似的求出不规则图形的面积