Thread: Defining an operaor

Hai,

I have some toubles with this question.

Define an operator * on by



a) is * commutative?
b) is * associative?

I can easily see that * is commutative, but how do i test for associativity?

The rule states that (x*y)*z = x*(y*z)

But what is z ?

Originally Posted by Jones

Hai,

I have some toubles with this question.

Define an operator * on by



a) is * commutative?
b) is * associative?

I can easily see that * is commutative, but how do i test for associativity?

The rule states that (x*y)*z = x*(y*z)

But what is z ?

* is associative if




Can you finish?

Spoiler:

Ah, thank you. I think i understand now. So the conclusion must be that the function is indeed associative because the two results are different?

Originally Posted by Jones

Ah, thank you. I think i understand now. So the conclusion must be that the function is indeed associative because the two results are different?

No - a function is associative if the two results are equal, not different.

The function is not associative (if Defunkt did his working right).

Originally Posted by Defunkt

* is associative if




Can you finish?

Spoiler:

Im sorry, some of the steps i do not understand.

= 2

Where did you get 2 from?