Question

C++

The roots of the quadratic equation ax² + bx + c = 0, a ≠ 0 are given by the following formula:

In this formula, the term b² - 4ac is called the discriminant. If b² - 4ac = 0, then the equation has a single (repeated) root. If b² - 4ac > 0, the equation has two real roots. If b² - 4ac < 0, the equation has two complex roots.

Instructions

Write a program that prompts the user to input the value of:

a (the coefficient of x²)

b (the coefficient of x)

c (the constant term)

The program then outputs the type of roots of the equation.

Furthermore, if b² - 4ac ≥ 0, the program should output the roots of the quadratic equation.

(Hint: Use the function pow from the header file cmath to calculate the square root. Chapter 3 explains how the function pow is used.)

Answer 1

#include <iostream>
#include <cmath>

using namespace std;

int main(int argc, char* argv[])
{

    double a, b, c, root1, root2, d;

    cout << "Enter a: ";
    cin >> a;
    cout << "Enter b: ";
    cin >> b;
    cout << "Enter c: ";
    cin >> c;

   d = b * b - 4.0 * a * c;
    if (d < 0)
    {
        cout<<"Complex conjugates\n";
    }
    else if (d == 0)
    {
        cout<<"Repeated real roots\n";
        root1 = -b / (2.0 * a);
        root2 = -b / (2.0 * a);
        cout<<"Root = "<<root1<<endl;
    }
    else if (d > 0 )
    {
        cout<<"Real distinct roots\n";
        root1 =(-b + sqrt(d)) / (2.0 * a);
        root2 =(-b - sqrt(d)) / (2.0 * a);
        cout<<"Root1 = "<<root1<<endl;
        cout<<"Root2 = "<<root2<<endl;
    }
    return 0;
}