trapezoidal method

#include<stdio.h>

float f(float x)
{
    return (1.0/(1+x*x));
}



int main()
{
    int i,n;
    float h,xn,x0,a,sum,temp;


    printf("\nEnter the upper and lower limits");
    scanf("%f %f",&xn,&x0);
    printf("\nEnter the no of intervals");
    scanf("%d",&n);

    printf("\n\na\t\tf(a)");

    h=(xn-x0)/n;
    sum=f(x0)+f(xn);
    for(i=1;i<=n-1;i++)
    {
        a=x0+i*h;
        sum+=2*f(a);
        printf("\n%f\t%f",a,f(a));
    }

    temp=(h/2)*sum;

    printf("\nThe ans is %.6f\n",temp);
}









OUTPUT:
Enter the upper and lower limits1 0

Enter the no of intervals6


a               f(a)
0.166667        0.972973
0.333333        0.900000
0.500000        0.800000
0.666667        0.692308
0.833333        0.590164
The ans is 0.784241
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