Talk:Sine of 72 Degrees

I don't believe that particular nested radical has a simple surd form --Ybab321 (talk) 01:20, 18 September 2014 (UTC)


 * Odd had a naive belief that *all* such expressions could be rendered as simple surds. May need research. --prime mover (talk) 05:02, 18 September 2014 (UTC)


 * $\sqrt{\sqrt5}$ itself cannot be simplified, acting as a counter-example. --kc_kennylau (talk) 12:41, 18 September 2014 (UTC)


 * Doesn't necessarily follow that $\sqrt {10 + 2 \sqrt 5}$ can't be simplified. After all, $\sqrt {8 - 4 \sqrt 3}$ simplifies to $\sqrt 6 - \sqrt 2$ -- see Sine of 15 Degrees. --prime mover (talk) 13:04, 18 September 2014 (UTC)


 * My point still holds: I believe it should be possible to express it in a form $a + \sqrt b + \sqrt c + \sqrt[4] d$ sort of thing, so as to convert the nestedness of the roots. --prime mover (talk) 13:07, 18 September 2014 (UTC)