import java.util.Scanner;
public class Polinom
{
public static void main ( String[] args )
{
System.out.print("Введите число");
}
public double polinom(double x)
{
Scanner number = new Scanner(System.in);
x = number.nextDouble();
double resultat = 3*Math.pow(x, 2)-8*x+4;
resultat = Math.round(resultat);
System.out.println(resultat);
System.out.print("Функция сработала");
return resultat;
}
}
Scanner number = new Scanner(System.in);
x = number.nextDouble();
в main>> java Polinom 21.3