/// <summary>
/// Evaluate a polynomial at an input point.
/// Uses Horner's method, first discovered by Persian mathematician
/// Sharaf al-Dīn al-Ṭūsī, which evaluates a polynomial by minimizing
/// the number of multiplications.
/// </summary>
/// <param name="x"></param>
/// <returns></returns>
public int EvaluateAt(int x)
{
var sum = 0;
foreach (var c in Coefficients.AsEnumerable().Reverse())
{
sum = sum * x + c;
}
return(sum);
}