Amusement for the grey matter
Brian Wood | 05/01/2019 10:04:04 |
2742 forum posts 39 photos | I found this in an old book of collected Mathematical puzzles selected from Scientific American magazine. It is the leader in my album pictures, I'm not sure how to include it in the text here The logic appears to be impeccable and it will work if 'c' is assigned the value of zero, but the general expression is compelling. I can imagine it it will appeal to Michael G especially Enjoy Brian Edited By Brian Wood on 05/01/2019 10:05:41 Edited By Brian Wood on 05/01/2019 10:06:31 |
John Hinkley | 05/01/2019 10:08:07 |
![]() 1545 forum posts 484 photos | Very puzzling! What exactly is the puzzle? Or is that what we're should be trying to figure out? Should even be a challenge for Michael G. John
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Michael Gilligan | 05/01/2019 10:09:54 |
![]() 23121 forum posts 1360 photos |
https://www.model-engineer.co.uk/albums/member_photo.asp?a=49837&p=820787 ... I must leave it 'til later MichaelG. |
JasonB | 05/01/2019 10:10:07 |
![]() 25215 forum posts 3105 photos 1 articles | Easy enough to work out what the puzzel is even without Michaels help Edit, beat me to it. Edited By JasonB on 05/01/2019 10:11:20 |
Andrew Johnston | 05/01/2019 10:15:35 |
![]() 7061 forum posts 719 photos | If c is zero then a-b is also zero so in the first step you multiply both sides by zero - to get 0=0. Just goes to show Kurt Godel was right. Andrew |
John Hinkley | 05/01/2019 10:16:12 |
![]() 1545 forum posts 484 photos | Didn't think to look there! John |
Gary Wooding | 05/01/2019 10:45:10 |
1074 forum posts 290 photos | The real answer is that if A=B+C then A-B-C=0, so, after factorisation you have Ax0 = Bx0, which is clearly correct for all values of A and B |
John Haine | 05/01/2019 10:58:58 |
5563 forum posts 322 photos | And it isn't a paradox. |
Andrew Tinsley | 05/01/2019 11:05:41 |
1817 forum posts 2 photos | The real snag is that you divide both sides by a-b-c which is equal to zero. Dividing by zero is a no, no as the result can have any value. Andrew. |
pgk pgk | 05/01/2019 11:29:18 |
2661 forum posts 294 photos | As is pointed out a-b-c=0 so as soon as you move ac to the left side of the equation you have 0=0 |
Georgineer | 05/01/2019 16:25:52 |
652 forum posts 33 photos | In my school days we had a proof that any number was greater than any number greater than itself, also achieved by the same trick of a hidden division by zero. There was also a geometrical proof that all right angles are obtuse. Regrettably, the details have evaporated in the ensuing half-century. George |
not done it yet | 05/01/2019 18:14:56 |
7517 forum posts 20 photos | Posted by Andrew Tinsley on 05/01/2019 11:05:41:
The real snag is that you divide both sides by a-b-c which is equal to zero. Dividing by zero is a no, no as the result can have any value. Andrew. Only zero divided by zero is indeterminate. Zero divided into anything else is actually infinity. The indeterminacy arises because the answer of any number divided by itself is one. |
Tim Stevens | 05/01/2019 23:00:04 |
![]() 1779 forum posts 1 photos | And as every schoolboy knows, (to end with a political message) there is nothing more indeterminate than unity. Cheers, Tim |
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