/// <summary>
/// Returns real roots of the specified polynomial which belongs to the specified interval
/// </summary>
/// <param name="input"></param>
/// <param name="lowerBound">lower boundary of the interval</param>
/// <param name="upperBound">upper boundary of the interval</param>
/// <returns></returns>
public static decimal[] RealRoots(Polynomial input, decimal lowerBound, decimal upperBound)
{
List<decimal> output = new List<decimal>();
Complex[] roots = input.Roots();
foreach (Complex c in roots)
{
if (c.IsReal() && !output.Contains((decimal)c.Re) && ((decimal)c.Re) >= lowerBound && ((decimal)c.Re) <= upperBound)
output.Add((decimal)c.Re);
}
return output.ToArray();
}
