The following example arrived in my email inbox a few weeks ago. It spurred a short but lively thread of discussion amongst some Maple developers.

I thought that it was interesting enough to post here. I'll hold off on giving my own opinion right away, because I'm curious to read what other MaplePrimes members might write about it.

> q := (6*((1/3)*a-1/9))/(36*a-116+12*sqrt(12*a^3-3*a^2-54*a+93))^(1/3);
                                   6 (a/3 - 1/9)
            q := --------------------------------------------------
                                       3      2             1/2 1/3
                 (36 a - 116 + 12 (12 a  - 3 a  - 54 a + 93)   )


> eval(q, a = 1/3); # this is the contentious part
                                       0


> eval(numer(q),a=1/3);
                                       0


> eval(denom(q),a=1/3);
                           /            1/2  1/2\(1/3)
                           |       4 676    9   |
                         3 |-104 + -------------|
                           \             3      /


> radnormal(%);
                                       0

Dave Linder
Mathematical Software, Maplesoft