Tell me more ×  So, in the course of last week's class work, I
ran across the Maple function surd() that takes the real part of
an nth root. However, conversation with my professor and my own
research have failed to produce even an adequate definition of
the term, much less a good reason for why it is used in that
context in Maple. Various dictionaries indicate that it refers
to certain subsets (perhaps all of?) the irrationals, while the
Wikipedia reference link uses it interchangeably with radical.
However, neither of those jive with the Maple interpretation as
$\mbox{Surd}(3,x) \neq\sqrt[3]{x}\;\;\;\;\;\;\;x<0$.  So, the
question is: what is a good definition for "surd"?  For bonus
points, I would be fascinated to see an origin/etymology of the
word as used in mathematical context.  share|improve this
question Do and answer your question? –  lhf Nov 21 '11 at 0:19
More accurately: for negative argument, surd() picks out the
real branch instead of the principal branch of the power
function if its first argu