C program for Newton Raphson method

/*newton raphson method*/

#include<stdio.h>

#include<math.h>

void

main()

{

                int count=0;

                float x0,xn,fx,dfx;

                printf("enter the guess value:");

                scanf("%f",&x0);

                /*iteration process*/

label: fx=(((1-x0*x0)*tan(x0))-x0);

                   dfx=(((1-x0*x0)*(pow(cos(x0),-2)))-(1+(2*x0*tan(x0))));

                   xn=x0-(fx/dfx);

                   if((fabs(xn-x0))<0.001)

                                   printf("\n the final root is %.4f \n",xn);

                   else

                   {x0=xn;

                   count=count+1;

                   if (count>100)

                   {

                                   printf("the solution does not converge");

                                   printf("enter a different guess value:");

                   }

                   else

                                   goto label;

                   }

}

RESULT:

enter the guess value:2 3

 the final root is 2.7437

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