#include <stdio.h> 
/* Propram to perform definite integration of a given function between two boundary limits input by user. Feel free to use and modify it, but please do not remove this comment. 
source: C for Engineering, http://c4engineering.hypermart.net */ 

#define N 1000 

void main(void) 
{ 
    float i,a,b,sum=0; 
    printf("\nThis program will integrate a function between two boundary limits."); 
    printf("\n\nEnter the first boundary limit:"); 
    scanf("%f",&a); 
    printf("\nEnter the second boundary limit:"); 
    scanf("%f",&b); 
    if(a>b){ i=a; a=b; b=i; } 
    for(i=a;i<b;i+=(b-a)/N) 
    { 
        /* Define your function below, and include the suitable header files */ 
        y=x*x+2*x-4; 
        sum+=y*(b-a)/N; 
    } 
    printf("\n\nValue of integration is:%.3f",sum); 
    getch(); 
    return; 
}