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Sunday, December 9, 2012

The legend of e and π


 The number π is a mathematical constant that is the ratio of a circle's circumference to its diameter. The constant, sometimes written pi, is approximately equal to 3.14159.

 The wonder of π is much more than the definition.















There are much more interesting formula about this constant, and maybe the only constant which can be equal to π is e.


This formula is called the most beautiful formula, you can know how e is important in math.
One piece of the beauty of math is connected together, two totally different definition can be connected inside. 



References: http://en.wikipedia.org/wiki/Pi
            http://en.wikipedia.org/wiki/E_(mathematical_constant)

Can all the 8-puzzle be solved?

   Do you ever play the game below?
   At first, the order of these numbers is in a mess, you can move the number to the blank. If you can place the order you win the game. So if you are given a 8-puzzle can you solve it? At first thought it seems can be solved easily. But it's not true!!!
   Here is the proof:
   Give the note [2 3 1 4 5 6 7 8 9] for the following 8-puzzle:
   Define the inverse order of the sequence. The inverse order of [2 3 1 4 5 6 7 8 9]  is two, for [2,1],[3,1] is disorder in the sequence.
      The movement when you solve the puzzle never change the even or odd of the inverse order.
      The inverse order of the target order [1 2 3 4 5 6 7 8] is even, Which means if you are given a puzzle, which disorder is odd, you can never solve it.
      You can play the trick on your friend, you already have the magic of math. Math can be the interesting part of life, right?




Math is the best epitaph of mathematician


   Many mathematicians regard math as their whole. They devoted everything to math. Here are some epitaphs of mathematician. We can see a little part of their amazing miracles. 
   Archimedes wanted no other epitaph than a sphere inscribed within a cylinder -- he had determined the sphere's relative volume and considered this his greatest achievement.

   Henry Perigal's tomb in Essex displays his graphic proof of the Pythagorean theorem.
(2)
     Gauss wanted to be buried under a heptadecagon, which he'd shown can be constructed with compass and straightedge. 
(3)

I can't dream about being someone like one these great mathematicians. But I want to get to know these great work done by these great men. If you can design your epitaph now, what do you expect on your epitaph?

References: 
(1).(3)http://www.guokr.com/article/69516/
(2)http://www.futilitycloset.com/2010/04/20/mathematicians-graves/

Wednesday, December 5, 2012

Wrong proof 2=1, just for fun

We will proof that 2=1!!!
1)
Let a = b
2)
Multiply 1) by a
a2 = ab
3)
Add a2 – 2ab to both parts of 2)
a2 + a2 – 2ab = ab + a2 – 2ab
4)
3) could be simplified:
2a2 – 2ab = a2 – ab
5)
It is the same as
2(a2 – ab) = 1(a2 – ab)
6)
Reduce 5) by (a2 – ab).
2=1

Where is a mistake?

Mistake is in the 6th step.
We can not divide by (a2 – ab) because a2– ab = 0.
a = b, so a2– ab = 0.

 

Tuesday, December 4, 2012

Beauty of Numbers


Here are some funny math interesting facts. All the below tricks are based around the sequential manipulation of the numbers being used for input and output.
Sequential Inputs of numbers with 8
1 x 8 + 1 = 9
12 x 8 + 2 = 98
123 x 8 + 3 = 987
1234 x 8 + 4 = 9876
12345 x 8 + 5 = 98765
123456 x 8 + 6 = 987654
1234567 x 8 + 7 = 9876543
12345678 x 8 + 8 = 98765432
123456789 x 8 + 9 = 987654321


Sequential 1's with 9
1 x 9 + 2 = 11
12 x 9 + 3 = 111
123 x 9 + 4 = 1111
1234 x 9 + 5 = 11111
12345 x 9 + 6 = 111111
123456 x 9 + 7 = 1111111
1234567 x 9 + 8 = 11111111
12345678 x 9 + 9 = 111111111
123456789 x 9 + 10 = 1111111111


Sequential 8's with 9
9 x 9 + 7 = 88
98 x 9 + 6 = 888
987 x 9 + 5 = 8888
9876 x 9 + 4 = 88888
98765 x 9 + 3 = 888888
987654 x 9 + 2 = 8888888
9876543 x 9 + 1 = 88888888
98765432 x 9 + 0 = 888888888


Numeric Palindrome with 1's
1 x 1 = 1
11 x 11 = 121
111 x 111 = 12321
1111 x 1111 = 1234321
11111 x 11111 = 123454321
111111 x 111111 = 12345654321
1111111 x 1111111 = 1234567654321
11111111 x 11111111 = 123456787654321
111111111 x 111111111 = 12345678987654321


Without 8
12345679 x 9 = 111111111
12345679 x 18 = 222222222
12345679 x 27 = 333333333
12345679 x 36 = 444444444
12345679 x 45 = 555555555
12345679 x 54 = 666666666
12345679 x 63 = 777777777
12345679 x 72 = 888888888
12345679 x 81 = 999999999


Sequential Inputs of 9
9 x 9 = 81
99 x 99 = 9801
999 x 999 = 998001
9999 x 9999 = 99980001
99999 x 99999 = 9999800001
999999 x 999999 = 999998000001
9999999 x 9999999 = 99999980000001
99999999 x 99999999 = 9999999800000001
999999999 x 999999999 = 999999998000000001
......................................


Sequential Inputs of 6
6 x 7 = 42
66 x 67 = 4422
666 x 667 = 444222
6666 x 6667 = 44442222
66666 x 66667 = 4444422222
666666 x 666667 = 444444222222
6666666 x 6666667 = 44444442222222
66666666 x 66666667 = 4444444422222222
666666666 x 666666667 = 444444444222222222
......................................
(http://www.testsherpa.com/images/Numbers1-10.gif)

Monday, December 3, 2012

Miracle of 2519


   Some numbers is very interesting, they have some special properties. Some of them can be very amazing. Here are some funny math interesting facts about this number 2519. Enjoy the Facts.
2519 Mod n means the reminder of 2519/n, here / is the integer division.
2519 Mod n
2519 Mod 2 = 1
2519 Mod 3 = 2
2519 Mod 4 = 3
2519 Mod 5 = 4
2519 Mod 6 = 5
2519 Mod 7 = 6
2519 Mod 8 = 7
2519 Mod 9 = 8
2519 Mod 10 = 9


Sequential Numbers with 2519
1259 x 2 + 1 = 2519
839 x 3 + 2 = 2519
629 x 4 + 3 = 2519
503 x 5 + 4 = 2519
419 x 6 + 5 = 2519
359 x 7 + 6 = 2519
314 x 8 + 7 = 2519
279 x 9 + 8 = 2519
251 x 10 + 9 = 2519

My Mathematics Bioloigy professor

    I am glad to introduce my mathematical biology professor Ronald Shonkwiler to you who devotes his all life to math and teaching, Ronald Shonkwiler.


1.       What makes you choose the mathematics as your lifetime career?

Shonk: My initial interest is engineer, and I have to learn a lot of math to learn engineer well. Then I found that mathematics is much fundamental and fascinating.

2.       What do you think mathematics can bring to our life or develop our life?

Shonk: Well, math is very useful in the daily life, for example forecasting how fast flu spreads, how much loss due to the earthquake.

3.       Well, I heard you hobby is flying, right? When did you have your first plane?

Shonk: Yes, I like to fly. I got my first plane about 10 years ago.

4.       Where do you learn how to fly?

Shonk: Well, I learned how to fly after I moved to Georgia, right in Georgia tech.

5.       How long did it take you to learn?

Shonk: About 10 months, but I didn’t learn every day. I you learn every day you can spend much less time.

6.       I heard you have made a plane by yourself, right?

Shonk: That’s right. It took me a lot of time. But it was very exciting, at first the plane were just pieces, then after the effort you could fly in the sky.

…

“Well if you are interested you can fly with me.” Then:
 



 
 
   Thanks my professor for the interview and the flying. What a nice guy he is , and I want to be a person like him, enjoy your job and enjoy the life. I think that’s the most happy life I have ever heard, I want to be a person like him. So what kind of life do you want in the future?