2 Given that
$$u _ { n } = \ln \left( \frac { 1 + x ^ { n + 1 } } { 1 + x ^ { n } } \right)$$
where \(x > - 1\), find \(\sum _ { n = 1 } ^ { N } u _ { n }\) in terms of \(N\) and \(x\).
Find the sum to infinity of the series
$$u _ { 1 } + u _ { 2 } + u _ { 3 } + \ldots$$
when
- \(- 1 < x < 1\),
- \(x = 1\).