- A sequence \(u _ { 1 } , u _ { 2 } , u _ { 3 } , \ldots\) is defined by
$$\begin{gathered}
u _ { 1 } = 3
u _ { n + 1 } = 2 - \frac { 4 } { u _ { n } }
\end{gathered}$$
- Find the value of \(u _ { 2 }\), the value of \(u _ { 3 }\) and the value of \(u _ { 4 }\)
- Find the value of
$$\sum _ { r = 1 } ^ { 100 } u _ { r }$$