- (a) Find the first four terms, in ascending powers of \(x\), of the binomial expansion of
$$( 1 + 8 x ) ^ { \frac { 1 } { 2 } }$$
giving each term in simplest form.
(b) Explain how you could use \(x = \frac { 1 } { 32 }\) in the expansion to find an approximation for \(\sqrt { 5 }\) There is no need to carry out the calculation.