5 The second term of a geometric series is 48 and the fourth term is 3 .
- Show that one possible value for the common ratio, \(r\), of the series is \(- \frac { 1 } { 4 }\) and state the other value.
- In the case when \(r = - \frac { 1 } { 4 }\), find:
- the first term;
- the sum to infinity of the series.