Understanding Associativity of Multiplication Modulo n

In summary, associativity for multiplication modulo n means that the result of a binary operation using three numbers (a, b, and c) is the same no matter which two numbers are multiplied first, as long as the final result is taken modulo n. This is possible because of the associative property of multiplication of integers.
  • #1
sush4sep
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0
please explain me associativity for multiplication modulo n
 
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  • #2
? Associativity for any binary operation is just (a*b)*c= a*(b*c). The point is that this allows us to extend the binary operation (defined for two operands) unambiguously to any number. I am not sure what you mean by "explain it for multiplication modulo n".

Perhaps this: let a, b c be numbers. Then (ab)c= a(bc) (mod n) if and only if (ab)c- a(bc) (mod n) which is the same as saying that (ab)c- a(bc), as an "ordinary" number, is a multiple of n. But in fact, because the usual multiplication of integers is associative, (ab)c= a(bc) so (ab)c- a(bc)= 0= 0(n) is a multiple of n.
 

1. What is the definition of associativity of multiplication modulo n?

Associativity of multiplication modulo n refers to the property where the order in which numbers are multiplied does not affect the final result when working with modular arithmetic. In other words, when performing multiplication modulo n, the parentheses can be placed around any two numbers without changing the final result.

2. Why is understanding associativity of multiplication modulo n important?

Understanding associativity of multiplication modulo n is important because it allows for more efficient and simplified calculations in modular arithmetic. It also helps to better understand the properties and behavior of modular arithmetic, which is widely used in various fields of mathematics, computer science, and cryptography.

3. How is associativity of multiplication modulo n different from regular multiplication?

Unlike regular multiplication, associativity of multiplication modulo n follows a specific set of rules where the order of operations does not matter. This means that the parentheses can be rearranged without changing the final result. In regular multiplication, changing the order of operations can result in a different answer.

4. Can you provide an example of associativity of multiplication modulo n?

Yes, for example, let's consider the equation (2 * 3) * 4 (mod 5). This can be simplified to 6 * 4 (mod 5) = 4 (mod 5). Now, if we rearrange the parentheses to 2 * (3 * 4) (mod 5), we get the same final result of 4 (mod 5). This demonstrates the associativity property of multiplication modulo n.

5. How is associativity of multiplication modulo n used in real-world applications?

Associativity of multiplication modulo n is used in various real-world applications, such as cryptography, coding theory, and error-correcting codes. It is also used in computer algorithms and programming to optimize performance and reduce the complexity of calculations.

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