decimal ?

Code:

---

#include <iostream>
#include <cmath>
#include <iomanip>
using namespace std;

int main()
{
        float a, b, c;
        float x1, x2;
        float root, temp;

        cout << "Enter the coefficient of the quadratic function (a*x^2+bx+c): ";
        cin >> a >> b >> c;

        temp = (b*b) - (4*a*c);

        if(temp>=0)
        {
                root = sqrt(temp);

                x1 = (-b+root) / (2.0*a);
                x2 = (-b-root) / (2.0*a);
       
                if (x1==x2)
                {
                        cout << "The single root for the quadratic function -> x = "
                        << setprecision(2) << x1 << endl;
                }
                else
                {
                        cout << "The root for the quadratic function -> x = "
                        << setprecision(2) << x1 << " and " << setprecision(2) << x2 << endl;
                }
        }
        else
                cout << "Invalid input" << endl;

        system("pause");
        return 0;
}

---

when i enter 1 2 1, the output is -1. Why the output is -1 and not -1.00 ?

I believe you need to set the format flags to floating-point, something like this IIRC:

Code:

---

cout.setf(ios_base::fixed, ios_base::floatfield);

---

i declared all my variables as float .... but why it still come out as integer value ? even if i do not use the flag ... it should printf out float value right ? the value stored in each variable should be in decimal format rite ?

setprecision sets how precise it will be, up to 2 decimal places in this case...if both those are zero, then it wont print them out, but if the number was something like 1.2345 it prints out 1.23