TheAlgorithms-C/Computer Oriented Statistic.../Simpson's_1-3rd_rule.c

35 lines
600 B
C

#include<conio.h>
#include<stdio.h>
#include<math.h>
float f(float x)
{
return 1.0+x*x*x;
}
void main()
{
int i,n;
float a,b,h,x,s2,s3,sum,integral;
printf("enter the lower limit of the integration");
sacnf("%f",&a);
printf("enter the upper limit of the integration");
sacnf("%f",&b);
printf("enter the number of intervals");
sacnf("%d",&n);
h=(b-a)/n;
sum=f(a)+f(b);
s2=s3=0.0;
for(i=1;i<n;i+=3)
{
x=a+i*h;
s3=s3+f(x)+f(x+h);
}
for(i=3;i<n;i+=3)
{
x=a+i*h;
s2=s2+f(x);
}
intgeral=(h/3.0)*(sum+2*s2+4*s3);
printf("\nvalue of the integral =%9.4f\n",integral);
getch();
}