Write a well commented C++ program to implement Newton\'s method of finding the

Question

Write a well commented C++ program to implement Newton's method of finding the real roots of f (x) = 0 You may assume that a C++ function bool calcF (float x, float &v;, float &g;) is available to calculate the value of the desired function f(x) and f (x) at x, and return these values in the reference parameters v and g. CalcF(..) returns true if g is non zero, otherwise it returns false. Your program should provide a suitable input/output interface so that the user can choose different initial guesses and convergence limits.

Explanation / Answer

#include<bits/stdc++.h>

using namespace std;
int degre,i=0,cnt=0,flag=0;
int coef[10]={0};
float x=0,x2=0,t=0;

bool CalcF(float& x,float &v,float&g)
{
printf(" ******************************************************");
printf(" ITERATION X FX F'X ");
printf(" **********************************************************");

do
{
cnt++;
v=g=0;
for(i=degre;i>=1;i--)
{
v+=coef[i] * (pow(x,i)) ;
}
v+=coef[0];
for(i=degre;i>=0;i--)
{
g+=coef[i]* (i*pow(x,(i-1)));
}
t=x2;
x2=(x-(v/g));

x=x2;

printf(" %d %.3f %.3f %.3f ",cnt,x2,v,g);

}while((fabs(t - x))>=0.0001);
printf(" THE ROOT OF EQUATION IS %f",x2);

if(g==0)
return false;
return true;

}

int main()
{

  

  

cout<<"Enter Highest degree of polynomial:::: ";
cin>>degre;

for(i=0;i<=degre;i++)
{
printf(" x^%d::",i);
cin>>coef[i];
}

cout<<" ";

printf(" polynomial is ");
for(i=degre;i>=0;i--)//printing coeff.
{
printf(" %dx^%d",coef[i],i);
}

cout<<" Enter X---->";
cin>>x;
float v=0,g=0;
CalcF(x,v,g);

  

  
}

=============================================================================

akshay@akshay-Inspiron-3537:~/Chegg$ g++ newton.cpp
akshay@akshay-Inspiron-3537:~/Chegg$ ./a.out
Enter Highest degree of polynomial:::: 3

   x^0::-6

   x^1::-25

   x^2::-3

   x^3::4

   polynomial is 4x^3 -3x^2 -25x^1 -6x^0
Enter X---->2

******************************************************
ITERATION X FX F'X
**********************************************************
1 5.273 -36.000 11.000
2 3.954 365.139 276.983
3 3.266 95.580 138.926
4 3.030 19.739 83.439
5 3.000 1.973 66.984
6 3.000 0.029 65.029
7 3.000 0.000 65.000
   THE ROOT OF EQUATION IS 3.000000

=======================================================================

Related Questions

Navigate

• Browse (All)
• Browse W
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.