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Messages 12796 - 12825 of 13927   Oldest  |  < Older  |  Newer >  |  Newest
Messages: Simplify | Expand   (Group by Topic) Author Sort by Date ^
12796
... digits ... there ... and ... then ... OK, If you have n+1 numbers, 1,11,111,1111,11111,111111,...., two of them must have the same residue mod n, the...
ramsey2879
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Aug 1, 2007
1:06 pm
12797
... another ... of ... I ... of ... of ... Sorry I forgot to put the "hole" in the "pigeon". By the way,I think this "principle" is quite powerful. For...
lbitran
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Aug 2, 2007
9:08 pm
12798
... lemma: a power of 3 greater than 0 and ending in XYZ, each X,Y,Z being a digit from 0 to 9 must uniquely follow a power of 3 that has the 3 digit ending...
ramsey2879
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Aug 3, 2007
4:09 am
12799
A number that is all 1's base 10 (other than 1) can not be a square. There are two basic proofs for this. Can you find them?...
ramsey2879
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Aug 4, 2007
2:15 pm
12800
... Elementary: a square must be 0 or 1 modulo 4, but 1...1 equals 3 modulo 4 (except for 1 of course). http://www.mymathforum.com...
Julien Santini
julien_santini
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Aug 4, 2007
4:31 pm
12801
... Thats only one proof Try finding another proof that uses proof by contradiction and does not use mod arithmetic...
ramsey2879
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Aug 4, 2007
8:48 pm
12802
... <julien_santini@> ... does not Here is, I think, another proof: The only numbers whose squares end in a 1 are those with last digits 9 or 1. So, the...
lbitran
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Aug 5, 2007
2:14 am
12803
Beats me... perhaps some examples would make it more clear. You said " ....... lemma: a power of 3 greater than 0 and ending in XYZ, each X,Y,Z being a digit...
Naval
navaljokes
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Aug 5, 2007
5:11 am
12804
... Then I mentioned that -m could be substituted for the value of -1 within each of the parenthesis. ... Still other variable "b" and "w" to add to the mix. ...
ramsey2879
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Aug 5, 2007
4:54 pm
12805
... I agree that some more examples might help some to better understand. Not all endings can be a power of three, "000,002,004,005,006,008,010,..." which are...
ramsey2879
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Aug 5, 2007
5:32 pm
12806
... The sum of the geometric series 10^p + 10^(p-1) + 10^(p-2) + . . . + 1 constitures a number of all 1's. The sum of this series can also be written as...
cino hilliard
hillcino368
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Aug 5, 2007
5:38 pm
12807
... + 1 ... (10-1) = ... 3^2*k^2. So ... determine if ... This ... have ... *5^p is ... is false ... That is a solid proof in my book....
ramsey2879
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Aug 5, 2007
9:16 pm
12808
... + . . . ... 1)/ ... 1. ... we ... (p-1) ... 9k^2 ... Cino hilliard proof looks good to me. But, 10^p+10^(p-1)+...+10+1 is not (10^p-1)/9; it is...
lbitran
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Aug 7, 2007
2:33 am
12809
... You can modify your proposition and make it more general. "A number whose LAST TWO DIGITS ARE ONES can not be a perfect square" Demonstration: Consider a...
lbitran
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Aug 7, 2007
3:48 pm
12810
... Yikes! ... Should have been The sum of the geometric series 10^(p-1) + 10^(p-2) + . . . + 1 I quiclly remember the sum of a geometric series by adding a...
cino hilliard
hillcino368
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Aug 7, 2007
10:04 pm
12811
... minus sign on b, and for ... 10^10), a=0. For ... as the ... I just realized that I can prefix a letter to the number to indicate the number of exponents...
lojbaner
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Aug 8, 2007
12:37 pm
12812
Prove in more than one way that a isoceles right triangle cannot have all integer sides. I can think of 2 distinct proofs. there may be more. Enjoy, Cino...
cino hilliard
hillcino368
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Aug 8, 2007
6:13 pm
12813
Since, in this case, the hypothenuse will always be a side times square root of 2, which is an irrational number. It would be impossible for all sides to be...
Tarcisio Góes
tarcisiogoes
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Aug 8, 2007
7:16 pm
12814
... all ... 1. Since the hypotenuse is always longer than either leg, that means the lengths of the 3 sides are x, x, and sqroot(2x^2) = x*sqroot(2) So...
slim_the_dude
Offline
Aug 8, 2007
8:21 pm
12815
... have all ... (Sorry my last answer was a duplicate of somebody else's... for some reason his answer had not yet made it to my email.) Here's another way: ...
slim_the_dude
Offline
Aug 8, 2007
8:32 pm
12816
So far, we have assumed sqrt(2) is irrational. Perhaps we need to show this is the case *after* we prove the assertion which can also be stated more generally...
cino hilliard
hillcino368
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Aug 8, 2007
8:58 pm
12817
... indicate ... letters, ... would ... I am not sure what you mean, Please give examples for your notation to express the following: 123456 23456789 ...
ramsey2879
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Aug 9, 2007
1:03 am
12818
In a message dated 8/8/2007 3:59:19 PM Central Daylight Time, ... I don't think so, only that it's not an integer. stevo </HTML> [Non-text portions of this...
MorphemeAddict@...
lojbaner
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Aug 9, 2007
4:46 am
12819
In a message dated 8/8/2007 8:04:04 PM Central Daylight Time, ... A5'123456 A7'23456789 B1'14'1234567 12345678 (the space is not part of the notation) Letting...
MorphemeAddict@...
lojbaner
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Aug 9, 2007
4:54 am
12820
You are saying that that sqrt(2) is NOT irrational? If this is so, I gotta go back to study basic math, as I've always read it in all math books that sqrt(2)...
Tarcisio Goes
tarcisiogoes
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Aug 9, 2007
9:43 pm
12821
In a message dated 8/9/2007 4:43:57 PM Central Daylight Time, ... No, of course not. I'm saying that the assumption is only that sqrt(2) is not an integer....
MorphemeAddict@...
lojbaner
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Aug 10, 2007
9:59 am
12822
... What are the possibilities of the sqrt(2)? 1. It is a rational number 2. it is an irational number If we assume 2., then we also assume it is not an...
cino hilliard
hillcino368
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Aug 10, 2007
5:54 pm
12823
... Not so. If the square root of two is rational then for integer sides we make the two equal sides of the isoceles triangle equal to a multiple of the...
ramsey2879
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Aug 10, 2007
9:58 pm
12824
In one old Math Competition I found the following problem, but I could not find a solution. Could some member of the Group help me to solve it ? The problem...
lbitran
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Aug 11, 2007
2:21 am
12825
... could ... a ... maybe do powers of 3 mod 1,000 and look for a number which is next to a number divisible by 2^3 and a number divisible by 5^2. e.g. 023,...
ramsey2879
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Aug 11, 2007
4:14 am
Messages 12796 - 12825 of 13927   Oldest  |  < Older  |  Newer >  |  Newest
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