# Symbolic evaluation of Product

 F =
((1. - Subscript[p, 4])^(-Subscript[p, 3]) - (1. - Subscript[p, 4]*
Exp[-Subscript[p, 1]*Subscript[x, i]^Subscript[p,2]])^(-Subscript[p,3]))/
((1. - Subscript[p, 4])^(-Subscript[p, 3]) - 1.)

f = FullSimplify[D[F, Subscript[x, i]]]

L := Product[f, {i, 1, n}]  // AbsoluteTiming


In Mathematica 7.0, how can I get the Product expression shown above to evaluate in a reasonable time without specifying n?.

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• Do you expect it to have a nice form? It shouldn't, that I can see. – Patrick Stevens Oct 28 '15 at 7:45
• Notice that if I remove p1*p2*p3*p4 from density function f then Product[] works fine even though it takes long time. The question is why product[] does not work in the previous density function f ? – aaa Oct 28 '15 at 9:23