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Vol. 7 No 5 - Pi Mu Epsilon

Vol. 7 No 5 - Pi Mu Epsilon

Vol. 7 No 5 - Pi Mu Epsilon

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I<br />

Let CG = a,GF= b,CF=CA=CD= r,CE=x,ED= y,AE=u, andEF= v.<br />

Then we have<br />

orean, then DE/EC is rational.<br />

from similar triangles AEC and AFG.<br />

Then<br />

so DE/EC is rational when a, b, and r are integral, establishing the<br />

converse.<br />

If DE/EC = p/q is rational, with p even, take m = q + p/2 and<br />

2 2 2<br />

n = p/2 and let a' = 2tm, b' = m - n , and P' = m2 + n . Then we have<br />

+ at - bt- m2 t n2 + 2mn - m 2 + n - 2 n - p<br />

bt m2 - n2 m- n q y<br />

but this Pythagorean triangle with sides a', b', and r' is similar to<br />

triangle CFG.<br />

It is easy to find counterexamples showing that the stated theorem<br />

is quite false.<br />

Counterexamples were submitted by RICHARD A. GIBBS, BOB PRIELIPP,<br />

and ROBERT A.<br />

STUMP.<br />

Editor's comient.<br />

When confronted with her mistake, the proposer<br />

pwred that "after all, rational and integral are almost the same thing."<br />

Such pussy-footing evades the problem, but Zelda is a regular contributor<br />

of high quality, so this is no catastrophe.<br />

477. [Fall 19801 Pftopo.~ed by Solomon W. Gotomb, Univ&u^ty 06<br />

Southem Cati

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