﻿ C++ exercises and solutions: if else and logical operators (con.)

# C++ exercises and solutions: if else and logical operators (con.)

## C++ if else and logical operators (con.)

### Write a C++ program to compute the real roots of the equation: ax2+bx+c=0.

The program will prompt the user to input the values of a, b, and c. It then computes the real roots of the equation based on the following rules:
-if a and b are zero=> no solution
-if a is zero=>one root (-c/b)
-if b2-4ac is negative=>no roots
-Otherwise=> two roots
The roots can be computed using the following formula:
x1=-b+(b2-4ac)1/2/2a
x=-b-(b2-4ac)1/2/2a

Solution:

#include <cstdlib>
#include <iostream>
#include<iomanip>
#include<cmath>

using namespace std;

int main(int argc, char *argv[])
{
float a;
float b;
float c;
float delta;

cout<<"Enter values of a b c separated by space:";
cin>>a>>b>>c;
if(a==0 && b==0)cout<<"No root";
else if(a==0)cout<<"The equation has only one root:"<<-b/c;
else {
delta=b*b-4*a*c;
if(delta<0) cout<<"No root";
else cout<<"The equation has two roots:"<<"x="<<-b+sqrt(b*b-4*a*c)/(2*a)<<",x1="<<-b-sqrt(b*b-4*a*c)/(2*a);
}

cout<<"\n";
system("PAUSE");
return EXIT_SUCCESS;
}