用梯形法计算定积分 的近似值.（精确到0.0001）

//
#include
#include
#include
main()
{
int i,j,n;
double a=0,b=1;
double min=1e-4;
double function(double x);
double trape_integral_n(double a,double b,int *n,double min);
printf("y=%.11lf\n",trape_integral_n(a,b,&n,min));
getch();
}
double function(double x) /*积分函数*/
{
return sqrt(1+x*x);
}
double trape_integral_n(double a,double b,int *n,double min)
{
int i;
double h,x,sum1,sum2;
*n=1;
h=b-a;
sum2=(b-a)*(function(a)+function(b))/2;
do
{
sum1=sum2;
sum2=sum2/2;
(*n)*=2;
h/=2;
for (x=a+h;xmin);
return sum2;
}