r = rac(5 + \sqrt5)(1 - \sqrt5)(1 + \sqrt5)(1 - \sqrt5) = rac5 - 5\sqrt5 + \sqrt5 - 51 - 5 = rac-4\sqrt5-4 = \sqrt5. - AMAZONAWS

📅 March 6, 2026 👤 scraface

Mar 06, 2026

$r = rac{(5 + \sqrt{5})(1 - \sqrt{5})}{(1 + \sqrt{5})(1 - \sqrt{5})} = rac{5 - 5\sqrt{5} + \sqrt{5} - 5}{1 - 5} = rac{-4\sqrt{5}}{-4} = \sqrt{5}.$