PROGRAM FOR BISECTION METHOD

/* PROGRAM FOR BISECTION METHOD*/

#include<stdio.h>

#include<conio.h>

#include<math.h>

#include<stdlib.h>

#define f(x) (x*x*x-3*x+1)

void main()

{

int step2,i,maxitr;

float a,x,b,error;

clrscr();

printf("\n BISECTIOM METHOD FOR FINDING ROOTS.");

printf("enter error and max.ittiration\n");

scanf("%f%d",&error,&maxitr);

step2:

printf("enter a and b such that f(a)*f(b)<0\n");

scanf("%f%f",&a,&b);

if (f(a)*f(b)>0)

goto step2;

for(i=0;i<maxitr;i++)

{

x=(a+b)/2;

printf("\n%diteration,root is %0.4f",i+1,x);

if (f(x)*f(b)<0)

a=x;

else

b=x;

if (fabs((b-a)/b)<=error)

{

printf("root is %0.4f\n",x);

getch();

exit(0);

}

}

printf("solution does not converge in%d iteration \n",maxitr);

getch();

}

/*OUTPUT

Enter Error and Max.iteration

.000001

39

Enter a and b such that f(a)*f(b)<0

1 iteration, Root is 5000.5000

2 iteration, Root is 2500.7500

3 iteration, Root is 1250.8750

4 iteration, Root is 625.9375

5 iteration, Root is 313.4688

6 iteration, Root is 157.2344

7 iteration, Root is 79.1179

8 iteration, Root is 40.0589

9 iteration, Root is 20.5293

10 iteration, Root is 10.7646

11 iteration, Root is 5.8823

12 iteration, Root is 3.4412

13 iteration, Root is 2.2206

14 iteration, Root is 1.6103

15 iteration, Root is 1.3051

16 iteration, Root is 1.4577

17 iteration, Root is 1.5340

18 iteration, Root is 1.4959

19 iteration, Root is 1.5149

20 iteration, Root is 1.5245

21 iteration, Root is 1.5292

22 iteration, Root is 1.5316

23 iteration, Root is 1.5328

24 iteration, Root is 1.5322

25 iteration, Root is 1.5319

26 iteration, Root is 1.5321

27 iteration, Root is 1.5321

28 iteration, Root is 1.5321

29 iteration, Root is 1.5321 Root is 1.5321*/