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#11 bonanova



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Posted 23 March 2008 - 07:16 AM

What is product of :

(x - a) (x - b) ........ (x - z) ?

I've seen this product expanded and I suppose I could search for it. Too lazy. ;)
But clearly it has a x26 term and a abcdefghijklmnopqrstuvwxyz term.
What the other terms must look like can be seen by expanding the first four terms:

(x - a) (x - b)(x - c) (x - d) =

x4 [1] +
x3 [-a -b -c -d] +
x2 [ab + ac + ad + bc + bd + cd] +
x1 [-abc -abd -acd -bcd] +
x0 [abcd]
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The greatest challenge to any thinker is stating the problem in a way that will allow a solution.
- Bertrand Russell

#12 jword


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Posted 23 March 2008 - 12:46 PM

There is no ambiguity in the question initially posted, only ,as pointed out, sloppy wording. The question was to imply "each year the tree attained a height of double the previous year" without being too obvious, and still allow an element of ambiguity. However the posted version "rate of growth" was too forthright and to this version Noct was correct, although not the answer I intended. It appears some of the answers are confusing themselves by mixing what I might have been implying (which would have been the correct train of thought ,had I worded differently) with what I actually posted. So right answer, wrong question. :wacko:
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#13 Talha


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Posted 23 March 2008 - 04:16 PM

Spoiler for answer

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