Practic 18

abstract class Function
    {
        protected abstract double Func(double x);
        public double Count(double x)
        {
            return Func(x);
        }
    }

    class Line : Function
    {
        public readonly double A;
        public readonly double B;

        public Line(double a, double b)
        {
            A = a;
            B = b;
        }

        protected override double Func(double x)
        {
            return A*x + B;
        }
    }

class Kub : Function //При чем тут Kub?)
    {
        public readonly double A;
        public readonly double B;
        public readonly double C;

        public Kub(double a, double b, double c)
        {
            A = a;
            B = b;
            C = c;
        }

        protected override double Func(double x)
        {
            return A * x * x + B * x + C;
        }
    }

class Hyperbola : Function
    {
        public readonly double A;

        public Hyperbola(double a)
        {
            A = a;
        }

        protected override double Func(double x)
        {
            return A/x;
        }
    }