<< A partridge in a pear tree? I have to cry fowl. The puzzle was posted before Xgiving, so would not have a Xmas reference. Incidentally, when I wrote << Let v_n be the vector in R^(n-1) defined as (1/n, 2/n,...,(n-1)/n). Let w_n be the vector in R^(n-1) with the same coordinates in reverse order. Find the limit as n -> oo of the angle between v_n and w_n. (Try this without using numerical approximation or summation-of-powers formulae.)

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I didn't mean to suggest the puzzle is solvable by guesswork. --Dan