Thursday, June 19, 2014

more about Pythagorean triples

More about Pythagorean  triples


In  the Pythagorean triple (a,b,c) ,if all of them are even, it be a reducible set.  And if ‘a’ and ‘b’ are even ‘c’ will also be even. Hence In all the irreducible sets either ‘a’ or ‘b’ must  necessarily  be odd..All squares will have only certain number digits-1,4,7 and 9. .Since the sum of two squares  is equal to a square,the sum of number digits of a2 and b2 must be equal to the number digit of c2. It requires that the number digit of either a2 or b2 must be 9 so that the number digit of the remaining square in one side will ne equal to the number digit of c2. All numbers which are multiples of three will give number digit 9 for its square. Hence either ‘a’ or ‘b’ must be a multiple of three.If ‘a’ is multiple of three, then a2 will be divisible by three.It means that c2 – b2 is divisible by three.that either (c-b) or (c+b) must be divisible by three.

Tuesday, June 17, 2014


Pythagorean triples with given endings

Here is yet another method to identify Pythagorean triples with given endings.
The Pythagorean triples (a,b,c) satisfy the relation a2 + b2 = c2 .Let us try to find a series of Phythagorean triples ending with 3,4 and 5 (greatest)
The most general form for this set is
(10x+3)2 + (10y+4)2 = (10z+5)2. It gives a condition for the suitable values of x,y,and z.- 5(x2 + y2) +3x +4y = 5z(z+1)
The other requirement for the Pythagorean triples is a+b = c+2α ,where α may be either odd or even. When we apply this condition to our general form ,it predicts α takes only certain allowed values 1,6,11,16,21… and so on.
 α = 1 ; x+y = z
α = 6 ; x+y-1= z
α = 11 ; x+y-2 = z
α = 16 ; x+y -3 = z
When α = 1
5(x2 + y2) +3x +4y = 5 (x+y)(x+y+1) ,it is reduced to 10xy+2x+y = 0. The oly possibility is x=0;y=0 and z=0.
When α = 6
5(x2 + y2) +3x +4y = 5(x+y-1)(x+y) ,the required condition becomes x = 9y/[2(5y-4)].If x and y are positive integers,the pre determined endings will not altered.For example when y=1 then x = 9/2 which gives
Irreducible triple 72 + 242 = 252; When y=3 ;x=27/22  which gives 842 + 1872 = 2052
 When α = 11 ,the required condition becomes x = (19y-10)/(10y-18) with y being even.When y=2 ,x=14.It gives (143,24,145)
Y=4 gives (3,4,5)
Y=6 gives (583,1344,1465)
Y=8 gives (803,2604,2725)


New relations

New Reations with Pythagorean triples
A "Pythagorean Triple" is a set of positive integers, a, b and c that fits the rule:
a2 + b2 = c2
And when we make a triangle with sides a, b and c it will always be a right angled triangle
List of the First Few
Here is a list of the first few Pythagorean Triples (not including "scaled up" versions mentioned below):
(3,4,5)
(5,12,13)
(7,24,25)
(8,15,17)
(9,40,41)
(11,60,61)
(12,35,37)
(13,84,85)
(15,112,113)
(16,63,65)
(17,144,145)
(19,180,181)
(20,21,29)
(20,99,101)
(21,220,221)
(23,264,265)
(24,143,145)
(25,312,313)
(27,364,365)
(28,45,53)
(28,195,197)
(29,420,421)
(31,480,481)
(32,255,257)
(33,56,65)
(3,544,545)
(35,612,613)
(36,77,85)
(36,323,325)
(37,684,685)

c is the longest side of the triangle, called the "hypotenuse"
a and b are the other two sides such that a< c ,b< c but a+b > c.  It is noted that one of the numbers a or b is 3 or mutiplles of 3. Let
 a+b = c + α, where α is also a positive integer. Squaring both sides, we have
 α2 +2cα – 2ab = 0 Solving for α, we get α = - c + [c2 + 2ab]1/2. i.e, c2 + 2ab must be a square number.
It is again noted that the product of ab i.e., twice the area of the right angled triangle is equal to a multiple (β) of the circumference (a+b+c) of the  right angled triangle such that β = α/2 .Since β is also a positive integer, α must be even.


Sunday, June 8, 2014

Puzzle

Fun with  Mathematics
Puzzle
A smart boy used to play computer game ‘ Free cell’  every day  before he used his laptop for assigned work. The percentage of win is displayed after the game is over.The fraction in the percentage is not considered by the computer.. He aimed 100 % win but he scored only 50 % after playing 300 games.
To make it to be 51% how many wins successively  he has to score?  He was unable to win all the games then played. If he got this 51 % after playing 20 games , then how many games he won in 20 ?.
Answer
In the beginning games he won 150 out of 300.  Suppose he played x games and won in all the games,
Then the new winning percentage becomes  150 + x/(300 +x) = 51/100 .X must be at least 7.
In the additional 20 games he won x games to make  the winning percentage 51. Then

150+x /320 = 51/100  , x must be 14.