# include < iostream >
# include < cmath >
using namespace std ;
int main () {
int a, b, c;
cout << " Introduceti coeficientii ecuatiei (a*x^4 + b*x^2 + c = 0): " ;
cin >> a >> b >> c;
if (a == 0 ) {
// Ecuatia devine de gradul 2: b*x^2 + c = 0
if (b == 0 ) {
if (c == 0 ) {
cout << " Ecuatia are o infinitate de solutii ." << endl ;
} else {
cout << " Ecuatia nu are solutii ." << endl ;
}
} else {
double x1 = -c / b;
cout << " Ecuatia are solutiile : x1 = x2 = " << x1 << endl ;
}
} else {
int D = b * b - 4 * a * c;
if (D < 0 ) {
cout << " Ecuatia nu are solutii reale." << endl ;
} else if (D == 0 ) {
double x1 = 0 , x2 = 0 , x3 = -b / ( 2 * a), x4 = -b / ( 2 * a);
cout << " Ecuatia are doua solutii egale: x1 = x2 = " << x1 << ", x3 = x4 = " << x3 << endl ;
} else {
double r1 = sqrt ((-b + sqrt (D)) / ( 2 * a));
double r2 = sqrt ((-b - sqrt (D)) / ( 2 * a));
double x1 = r1, x2 = -r1, x3 = r2, x4 = -r2;
cout << " Ecuatia are patru solutii distincte: x1 = " << x1 << ", x2 = " << x2 << ", x3 = " << x3 << ", x 4 = " << x 4 << endl ;
}
}
return 0;
}