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Re: Solution to a problem!!



On Wed, 28 Oct 1998, Ludwik Kowalski wrote:

1) First simplify the problem a little by assuming that the
speed of rowing is the same as the speed of running. In this
case the solution is trivial, the boat should arrive to the other
shore exactly where the girl is.

Uh, oh ...

The tangent of the desired angle must be equal to the speed of water
divided by the speed of rowing.

What if the speed of the water is the same as that of the rowing and
running? What if it's greater!!? I think your strategy runs into
problems here. Clearly the boy can still reach the girl, but he'll
*never* get there if he tries to do what you suggest. This counterexample
is all it takes to show that your "trivial" solution is also wrong.

...
Is this a convincing argument?

Well ....

John
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A. John Mallinckrodt http://www.csupomona.edu/~ajm
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