Find the binomial expansion of \(( 1 + 5 x ) ^ { \frac { 1 } { 5 } }\) up to and including the term in \(x ^ { 2 }\).
Find the binomial expansion of \(( 8 + 3 x ) ^ { - \frac { 2 } { 3 } }\) up to and including the term in \(x ^ { 2 }\).
Use your expansion from part (b)(i) to find an estimate for \(\sqrt [ 3 ] { \frac { 1 } { 81 } }\), giving your answer to four decimal places. [0pt]
[2 marks]