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www.carom-maths.co.uk. Activity 2-14: Hikorski Triples. What does. m ean to you?. If . Putting this another way: . is the answer, what is the question? . What do the expressions. We can broaden this out :. m ean to you?. The Theory of Special Relativity tells us that nothing
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www.carom-maths.co.uk Activity 2-14: Hikorski Triples
What does mean to you?
If Putting this another way: is the answer, what is the question?
What do the expressions We can broaden this out: mean to you?
The Theory of Special Relativity tells us that nothing can travel faster than the speed of light. So if a train is travelling at 2/3 the speed of light, and a man is travelling at 4/5 the speed of light relative to the train, how fast is he travelling? Suppose we say the speed of light is 1. We can add two parallel speeds like so: Task: show that if |a|, |b| < 1, then |(a + b)/(1 + ab)| < 1.
You may not have met the functions tanh(x) and coth(x) yet, but when you do you will find that
GCSE Resit Worksheet, 2002 How many different equations can you make by putting the numbers into the circles? Solve them!
Suppose a, b, c, and d are in the bag. If ax + b = cx + d, then the solution to this equation is x = There are 24 possible equations, but they occur in pairs, for example:ax + b = cx + d and cx + d = ax + b will have the same solution. So there are a maximum of twelve distinct solutions.
This maximum is possible: for example, if 7, -2, 3 and 4 are in the bag, then the solutions are:
If x is a solution, then –x, 1/x and -1/x will also be solutions. ax + b = cx + d a + b(1/x) = c + d(1/x) c(-x) + b = a(-x) + d a + d(-1/x) = c + b(-1/x)
So the solutions in general will be:{p, -p, 1/p, -1/p}{q, -q, 1/q, -1/q}and {r, -r, 1/r, -1/r}where p, q and r are all ≥ 1. Are p, q and r related?
It is possible for p, q and r to be positive integers. For example, 1, 2, 3 and 8 in the bag give (p, q, r) = (7, 5, 3). In this case, they form a HikorskiTriple (or HT).
Are (7, 5, 3) linked in any way? Will this always work?
a, b, c, d in the bag gives the same as a + k, b + k, c + k, d + kin the bag. Remember ... Translation Law
a, b, c, d in the bag gives the same as ka, kb, kc, kdin the bag. Remember ... Dilation Law So we can start with 0, 1, a and b (a, b rational numbers with 0 < 1 < a < b)in the bag without loss of generality.
a, b, c, d in the bag gives the same as -a, -b, -c, -din the bag. Reflection Law (Dilation Law with k = -1)
Suppose we have 0, 1, a, bin the bag, with 0 < 1 < a < band with b – a < 1 then this gives the same as –b, – a, – 1, 0 which gives the same as 0, b – a, b – 1, b which gives the same as 0, 1, (b – 1)/(b – a), b/(b – a) Now b/(b – a) – (b – 1)/(b – a) = 1/(b – a) > 1
If the four numbers in the bag are given as {0, 1, a, b} with 1< a < b and b – a > 1, then we can say the bag is in Standard Form. So our four-numbers-in-a-bag situation obeys three laws: the Translation Law, the Reflection Law and the Dilation Law.
Given a bag of numbers in Standard Form,where might the whole numbers for our HT come from?
(b – 1)/a must be the smallest of these. The only possible whole numbers here are Either one of could be the biggest.
Task: check out the following - So the only possible HTs are of the form (p, q, r) where r = (pq + 1)/(p + q), And where p q r are all positive integers.
We now have that the twelve solutions to our bag problem are:
Pythagorean Triples This has the parametrisation(2rmn, r(m2 - n2), r(m2 + n2)) Choosing positive integers m > n, r always gives a PT here, and this formula generates all PTs. Hikorski Triples Do they have a parametrisation?
How many HTs are there? Plenty... All n > 2 feature in at least 4 HTs.
On the left are the smallest HTs (a, b, c), arranged by the product abc of their three elements. Is abcunique for each HT? The Uniqueness Conjecture If (a, b, c) and (p, q, r) are non-trivial HTs with abc = pqr, then (a, b, c) = (p, q, r).
Why the name? I came up with the idea of an HT by writing my GCSE Equations Worksheet back in 2002. • I needed a name for them, and at the time • I was playing the part of a bandleader • In the College production of They Shoot Horses, Don’t They? • The name of the bandleader was Max Hikorski, • and so Hikorski Triples were born.
With thanks to:Mandy McKenna and Far East Theatre Company. Tom Ward, Graham Everest, and Shaun Stevens. Carom is written by Jonny Griffiths, mail@jonny-griffiths.net