What is the error in this program?

Question

#include<conio.h>

int main()

{

//*SOLVING QUARDRATIC EQUATION FOR "X"

int a,b,c,x1,x2,d;

    cout<<"enter coefficients a,b and c";

    cin>>a>>b>>c;

    d=b*b-4*a*c;

    if(d>0)

    {

        x1=(-b+sqrt(d))/(2*a);

        x2=(-b-sqrt(d))/(2*a);

        cout<<"two real solution."<<endl;

        cout<<"x1="<<x1<<endl;

        cout<<"x2="<<x2<<endl;

    }

    else if(d==0)

    {

        cout<<"one real solution."<<endl;

        x1=(-b+sqrt(d))/(2*a);

        cout<<"x1=x2"<<x1<<endl;

    }

    else

    cout<<"no real solutions."<<endl;

    getch();

    return 0;

}

Answer 1

include <math.h> header file for sqrt function

Answer 2

#include<stdio.h>

Answer 3

#include<stdio.h>

Answer 4

#include<iostream.h> not included.

Answer 5

#include<iostream>

#include<math.h>

using namespace std;

to write after including conio header file