Simpson.cpp

//Simpson's1/3rule
#include<iostream>
#include<cmath>
#define f(x)(sin(x))
using namespace std;
int main()
{
float a,b,sum,n,h;
int i;
cout<<"Enter Initial Limit of x (a):";
cin>>a;
cout<<"Enter Final Limit of x (b):";
cin>>b;
cout<<"Enter Number Of Intervals n:";
cin>>n;
h=(b-a)/n;
sum=(f(a)+f(b));
for(i=1;i<n;i++)
{	
	if(i%2==0)
	sum=sum+2*f(a+(i*h));
	else
	sum=sum+4*f(a+(i*h));
}
sum=sum*h/3;
cout<<sum;
return 0;
}