/* This program finds area of the function by Trapezoidal Rule*/
#include<stdio.h>
#include<math.h>
float area(float a)
{
float f;
f=1/(sqrt(1+a*a));
return (f);
}
void main()
{
int i,n;
float a,b,h, sum1,sum2,sum;
clrscr();
printf(" Type the lower limit a and upper limit b\n");
scanf("%f%f", &a,&b);
printf(" Type the number of interval n\n");
scanf("%d", &n);
sum1=area(a);
sum1+=area(b);
sum2=0;
h=(b-a)/n;
for(i=1;i<n;i++)
sum2+=area(a+i*h);
sum=h*(sum1+2*sum2)/2;
printf(" The required area = %8.4f\n", sum);
getch();
}