public void SqrtIrrational()
    {
        var expected = BigRational.SqrtAsRationals(2).Skip(100).First();
        var actual   = BigRational.Sqrt(new(2), 13);

        Assert.True(BigRational.Abs(expected - actual) < new BigRational(1, 1000000000));
    }
    public void SqrtAsRational()
    {
        var expected = new BigRational[]
        {
            new(1, 1),
            new(3, 2),
            new(7, 5),
            new(17, 12),
            new(41, 29),
        };
        var actual = BigRational.SqrtAsRationals(new BigInteger(2)).Take(5);

        Assert.True(expected.SequenceEqual(actual));
    }