Secant_Method.c

//C Program to Implement Secant Method
#include<stdio.h>
#include<math.h>
#define EPSILON 0.0001  //to find answers till 4 correct decmal places
float findValueAt(float x)
{
   return x*x*x - 5*x +1;
   //return cos(x)+2*sin(x)+x*x; transcedental Equation
}

float findX(float x1,float x2)
{
      return (x1*findValueAt(x2) - x2 * findValueAt(x1)) / (findValueAt(x2) - findValueAt(x1));
}
int main()
{
    int maxIteration,i=1;
    float x1,x2,x;
    printf("Enter x1 and x2\n");
    scanf("%f%f",&x1,&x2);
    printf("Enter Maximum no of Iterations\n");
    scanf("%d",&maxIteration);
    
    x = findX(x1,x2);   
    do
    {
      x1=x2;
      x2=x;
      printf("Iterations=%d  Root=%f\n",i,x);   
      x = findX(x1,x2);  
      if(fabs(x-x2)<EPSILON)
      { 
          printf("Final Root=%f  Total Iterations=%d",x,i+1);
          return 0;

      }
      i++; 
    }while(i<=maxIteration);
    printf("Final Root=%f",x);

    return 0;
}