Interesting to also know that…. ]]>

defines the lemniscate cotangent = (X/Y) = T

where X = T/(T + 1) ]]>

You may want to see this post by Robert Israel who answered my question at http://math.stackexchange.com/questions/153504.

]]>The reduced form of the sextic you mentioned does not have a concise form. You have to go through TWO Tschirnhausen transformations, a quadratic and quartic one. I described an easy approach in “A New Way to Derive the Bring-Jerrard Quintic”, the 18th file in http://sites.google.com/site/tpiezas/ramanujan. (While I discuss there the quintic, I trust you can extrapolate it for the sextic.)

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