Unit 4.4 All in one program for all three methods

#include<stdio.h>
#include<math.h>
#define f(x) sin(x) - log(x) + exp(x)
int main(){
    int n,i;
    float x[15],sum_ex=0,a,b,h;

    float sum_mid=0,ans_tre; // trapezoildal

    float sum_even =0 , sum_odd = 0,ans_simp_13; // simpson 1/3

    float sum_3div = 0 , sum_3nondiv = 0,ans_simp_38; // simpson 3/8

    printf("Enter the value of lower and upper limit and h\n");
    scanf("%f %f %f",&a,&b,&h);

    n = ceil(((b-a)/h));

    for(i=0 ; i<=n ; i++){
        x[i] = a + (h*i);
    }

    sum_ex = f(x[0]) + f(x[n]);

    // trapezoildal start here ---------------------------

    for(i=1 ; i<n ; i++){
        sum_mid +=(f(x[i]));
    }

    ans_tre = (h/2) * ( sum_ex + (2*sum_mid) ) ;

    printf("ans trapezoildal %f\n",ans_tre);

    // trapezoildal end here ---------------------------


    // simpson 1/3 start here ---------------------------

    for(i=1 ; i<n ; i++){
        if(i%2 == 0)
            sum_even += f(x[i]);
        else
            sum_odd += f(x[i]);
    }

    ans_simp_13 = (h/3) * (sum_ex + (4*sum_odd) + (2*sum_even));

    printf("ans simpson 1/3 rd %f\n",ans_simp_13);
    // simpson 1/3 end here ---------------------------


    // simpson 3/8 start here ---------------------------

    for(i=1 ; i<n ; i++){
        if(i%3 == 0)
            sum_3div += f(x[i]);
        else
            sum_3nondiv += f(x[i]);
    }
    ans_simp_38 = (3*h)/8 * (sum_ex + (3*sum_3nondiv) + (2*sum_3div));

    printf("ans simpson 3/8 rd %f\n",ans_simp_38);
    // simpson 3/8 end here ---------------------------

     return 0;
}

/*
Output
Enter the value of lower and upper limit and h
0.2 1.4 0.1
ans trapezoildal 4.056173
ans simpson 1/3 rd 4.051058
ans simpson 3/8 rd 4.051161
*/