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From: wws@whuxlm.UUCP (Stoll W William)
Newsgroups: net.puzzle
Subject: x^x^x^... and MAA tests
Message-ID: <750@whuxlm.UUCP>
Date: Fri, 26-Apr-85 18:10:43 EST
Article-I.D.: whuxlm.750
Posted: Fri Apr 26 18:10:43 1985
Date-Received: Sat, 27-Apr-85 06:30:10 EST
Distribution: net
Organization: AT&T Bell Laboratories, Whippany
Lines: 23

To restate the problem:

x^x^x^... = 2     What is x?

x is the square root of 2 -- The test answer key says to use substitution:

x^(x^x^x^...) = 2	Substitute 2 for the expression in parentheses,

x^2 = 2

This question appeared on the 1973 MAA test I think -- I didn't get it
right (just a dumb 9th grader), but I always bring it up when conversation
turns to puzzles.  It's interesting that it reappeared in another form
in 1984 (someone else pointed out).

I was really glad to get the opportunity to take those tests and compete
nationwide with my peers at something.  Later I did it with the Putnam
exam (and didn't do so well; I got a 16 out of 120 once).  I even won
some savings bonds in '75 and '76.

Any other MAA braggarts out there?

Bill Stoll, ..!whuxlm!wws