- (a) Find, in ascending powers of \(x\), the first four terms of the binomial expansion of
$$( 1 - 9 x ) ^ { \frac { 1 } { 2 } }$$
giving each term in simplest form.
(b) Give a reason why \(x = - \frac { 2 } { 9 }\) should not be used in the expansion to find an approximation to \(\sqrt { 3 }\)