Understanding Odd and Even Permutations in Linear Algebra - Quick Help

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To determine if a permutation is odd or even, count the number of 2-cycles it can be expressed as. A permutation is classified as even if it can be represented as the product of an even number of 2-cycles, while it is odd if it cannot. For example, the permutation (1 2 3 4) is odd because it can be expressed as three 2-cycles, while (1 3)(2 4) is even as it consists of two 2-cycles. Understanding this distinction clarifies the classification of permutations in linear algebra. This foundational concept is crucial for further studies in the subject.
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Linear Algebra help -urgent!

Hi,
I'm doing a bit of self learning on Linear Algebra but I'm kinda confused with the information given on odd and even permutations?

How do you determine whether a permutation is odd or even?

For example, the book has given some examples such as:

(1 2 3 4) is odd, (1 3)(2 4) is even? :confused:

Can someone help please? Thank you!
 
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Try to count the 'steps' you need to do a permutation and see if the number is odd or even.
 
A permutation is even if it's the product of an even number of 2-cycles. That's why (1 3)(2 4) is even. A permutation is odd if it isn't even. (1 2 3 4 ) written as two cycles would be (1 4)(1 3)(1 2) which is odd.
 
Thanks guys! I get it now :biggrin:
 
Question: A clock's minute hand has length 4 and its hour hand has length 3. What is the distance between the tips at the moment when it is increasing most rapidly?(Putnam Exam Question) Answer: Making assumption that both the hands moves at constant angular velocities, the answer is ## \sqrt{7} .## But don't you think this assumption is somewhat doubtful and wrong?

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