5. Use the binomial expansion to evaluate, root 26 to five decimal places.
Hint: Express 26 as 5^2 + 1
6. is root y^2 + z^2? Motivate your answer.
5. You mean $\displaystyle \sqrt{26}$?
hint: $\displaystyle (1+x)^m = 1 + mx + \frac{m(m-1)}{2!} x^2 + \frac{m(m-1)(m-2)}{3!} x^3 + ... $
$\displaystyle + \frac{m(m-1)(m-2)...(m-(k-1))}{k!}x^{k} + ...$
so, $\displaystyle (1+5^2)^{1/2}$.. let $\displaystyle x = 5^2$ and $\displaystyle m = \frac{1}{2}$