public static void Main()
double basefig, altura1,altura2, x;
double partes = 8, area = 0;
double lim_inf = 3, lim_sup = 8;
basefig = (lim_sup-lim_inf)/partes;
altura1 = -Math.Pow(x, 3)+10*Math.Pow(x, 2)+8*x+10;
altura2 = -Math.Pow(x, 3)+10*Math.Pow(x, 2)+8*x+10;
area = area + ((altura1+altura2)*basefig)/2;
Console.WriteLine("El area (integral) es: "+area);