trapizoidal rule.c

#include<stdio.h>
#include<stdlib.h>
#include<conio.h>
//float *coll;
//coll=(float*) malloc(n+1 * sizeof(float));
//float del = (b-a)/n;

float f(float x)
{
    return ((3*x*x)+(2*x)-5);
}

int main()
{
    float a=0.0,b=2.0,n=6.0,sum=0,result;
    float coll[7],fn[7];
    int i,j,k,g;
    float del = (b-a)/n;

    for(i=0;i<=n;i++)
    {
        if(i==0)
        { coll[i]=a;}
        else if(i==n)
        { coll[i]=b; }
        else
        { coll[i]= coll[i-1]+del;}
    }
    for(j=0;j<=n;j++)
    {
        if(j==0 || j==n)
        { fn[j] = f(coll[j]);}
        else
        { fn[j] = 2*f(coll[j]);}
    }
    printf("intervals are :\n");
    for(g=0;g<=n;g++)
    {
        printf("%f,",coll[g]);
    }
    printf("\n");
    for(k=0;k<=n;k++)
    {
                sum = sum+fn[k];
                printf("\nf(%d) = %f",k,fn[k]);
    }
    result = (del/2.0) * sum;
    printf("\ntrapizoidal rule result ==>%f",result);
    return 0;
    }