LICHOBEZNIKOVA METODA
#include <stdio.h>

#include <math.h>

double f(double);

void main()

 {

   int i,n,nmin,nmax;

   double a,b,h,p,Ln,L2n,eps,;

   printf(“Zadej a,b,eps,nmin,nmax: ”);

   scanf(“%lf,%lf,%lf,%i,%i”,&a,&b,&eps,&nmin,&nmax); 

   printf(“Vypocet integralu funkce sin (x) / x od %f do %f lichobeznikovou metodou”,a,b);

   n=1;

   h=(b-a)/2;

   L2n=h*(f(a)+f(b));

   printf(“    n            Ln\n\n”);

   do

     {

      Ln=L2n;printf(“ %4i %20.7f\n”,n,Ln);

      p=0;

      for(i=1;i<=n;i++)   p+=f(a+(2*i-1)*h);

      L2n=.5*Ln+h*p;

      n=2*n;

      h=.5*h;

     }

    while((fabs(L2n-Ln)>=eps || n<nmin) && n<=nmax)

    if(n>nmax) printf(“Presnost nedosazena.\n”);

      else printf(“Presnost dosazena pri deleni intervalu na  %4i dilku \n”,n,);

   printf(“ %4i %20.7f\n”,n,L2n);

 }



SIMPSONOVA METODA
#include <stdio.h>

#include <math.h>

double f(double);

void main()

 {

   int i,n,nmin,nmax;

   double a,b,h,p,L,sn,s2n,eps,;

   printf(“Zadej a,b,eps,nmin,nmax: ”);

   scanf(“%lf,%lf,%lf,%i,%i”,&a,&b,&eps,&nmin,&nmax); 

   printf(“Vypocet integralu funkce sin (x) / x od %f do %f  Simpsonovou metodou”,a,b);

   n=1;

   h=(b-a)/2;

   L=h*(f(a)+f(b));

   s2n=1e10;

   printf(“    n            s2n\n\n”);

   do

     {

      sn=s2n;

      p=0;

      for(i=1;i<=n;i++)   p+=f(a+(2*i-1)*h);

      s2n=1./3.*(L+4*h*p);

      L=L/2+h*p;

      n=2*n;

      h=.5*h;

      printf(“ %4i %20.7f\n”,n,s2n);

     }

    while((fabs(s2n-sn)>=eps || n<nmin) && n<=nmax)

   if(n>nmax)printf(“Presnost nedosazena.\n”);

     else printf(“Presnost dosazena pri deleni intervalu na %4i dilku \n”,n);

 }

double f(double x)

 {

   return (x==0) ? 1 : sin(x)/x;

 }