include stdio include stdlib include math double integ double double i

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
double integ(double(*f)(double),int,int,int);
double f1(double);
double f2(double);
int main(void)
{
    double s,a,b,(*p)(float);
    int n,k,i;
    do{
        printf("Input number of F\n");
      scanf("%d",&k);
    }
    while(k>2 || k<1);
    for(i=1;i<=k;i++)
    {
        switch(i)
        {
        case 1:a=3;b=-1;p=f1;break;
        case 2:a=5;b=1;p=f2;break;
    }
    n=35;
    do
    {
        s=integ(p,a,b,n);
        n*=2;
        printf("integral=%lf n=%d\n",s,n);
    }
    while(fabs(s-integ(p,a,b,n)>1e-5));
    printf("\n");
    }
    return 0;
}
double integ(double(*f)(double),int a,int b,int n)
{
    double h,s=(f(a)+f(b))/2;
    double i;
    h=(double)(b-a)/n;
    for(i=a+h;i<=b-h;i+=h)
        s+=f(i);
    return s*=h;
}
double f1(double x){
return 1/(3*x*x-2*x+4);
}
double f2(double x)
{
    return cos(x)/(1+sin(x)*sin(x));
}