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What is wrong with my code?

newton123 (32)
Help me please! i keep on seeing this error!

cannot convert `double' to `double*' for argument `1' to `double get_fx(double*, int, double, double, double)'

here is my code.


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#include <iostream>
#include <math.h>


using namespace std;

int input_pol(double coef[],int& Pow);
double get_fx(double coef[],int Pow,double l,double x,double fx);

double falsi(double, double);

const int MAX = 1000;
void d1();
void d2();
void d3();
void d4();


int main()
{
    
    double coef[1000];
    double xnew[MAX], xplus[MAX], xminus[MAX];
    int imax, Pow;
    
    input_pol(coef,Pow);
    

    
    
    cout << endl;
    cout << "Enter first guess: ";
    cin >> xplus[0];
    cout << endl;
    cout << "Enter Second guess: ";
    cin >> xminus[0];
    cout << endl;
    cout << "Set maximum iteration: ";
    cin >> imax;
    
    for(int i = 0; i < imax; i++)
    {
            xnew[i] = falsi(xplus[i], xminus[i]);
            
           if(get_fx(xnew[i])> 0)
            {
                         xplus[i+1] = xnew[i];
                         xminus[i+1]=xminus[i];
            }
            else
            {
                         xminus[i+1] = xnew[i];
                         xplus[i+1]=xplus[i];
            }
    }
    cout << endl << endl;
    for(int i = 0; i < imax; i++)
    {
            cout.setf(ios::fixed);
            cout.setf(ios::showpoint);
            cout.precision(20);
            cout << xnew[i] << endl;
    }
    
    cout << endl << endl << endl;
    cout << "The Approximate root is: ";
    
    cout.setf(ios::fixed);
    cout.setf(ios::showpoint);
    cout.precision(20);
    cout << endl << endl << xnew[imax - 1];
    
    cin.get();
    cin.get();
    
    return 0;
}
int input_pol(double coef[],int& Pow)
{
    cout<<"Enter the highest degree in the polynomial: ";
    cin>>Pow;
    cout<<endl;
    for(int i=Pow;i>=0;i--)
    {
            cout<<"Enter the coefficient of each term with thier corresponding sign."<<endl;
            cout<<i+1<<" term: ";
            cin>>coef[i];
            cout<<coef[i]<<"x^"<<i<<endl;
    }
}
double get_fx(double coef[],int Pow,double l,double x,double fx)
{
       
    for(int i=Pow;i>=0;i--)
    {  
       l+=(coef[i]*pow(x,i));
       fx=l;      
    }
     return fx;
}

double falsi(double xp, double xm)
{
       return xp - get_fx(xp) *(xp - xm)/(get_fx(xp) -get_fx(xm));
}




Last edited on
Yanson (885)
this is the problem
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double falsi(double xp, double xm)
{
	return xp - get_fx(xp) *(xp - xm) / (get_fx(xp) - get_fx(xm));
}


xp is of type double you then have get_fx(xP) the first parameter of get_fx is a double pointer* not a double. not to mention that get_fx takes more than one parameter

if(get_fx(xnew[i])> 0)
again get_fx takes more than one parameter
newton123 (32)
thank you for that.. do you know how to fix it? i have to submit it tomorrow. I'm so tired!
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