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## 'Archimedes Numerical Roots' printed from http://nrich.maths.org/

A sequence of numbers $x_1, x_2, x_3, ... ,$ starts with $x_1 = 2$,
and, if you know any term $x_n$, you can find the next term
$x_{n+1}$ using the formula $x_{n+1} = \frac{1}{2} \left( x_n +
\frac{3}{x_n} \right)$.