Injective Property of Rotation Function (x,y) to (y,x)

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The discussion centers on whether the function that maps (x,y) to (y,x) is injective. To determine injectivity, it is necessary to show that if f(x,y) = f(x',y'), then (x,y) must equal (x',y'). The participants conclude that since the ordered pairs are equal, it follows that y = y' and x = x', confirming the injective property. The final consensus is that the function is indeed injective. The reasoning provided is deemed sufficient to establish this conclusion.
dpa
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Hi all,

Q. A function takes (x,y) and gives (y,x). Is this function injective?

For any function to be injective, f(x,y)=f(x',y')=>(x,y)=(x',y').
But here, I get,
(y,x)=(y',x')
How can I show the function is injective? It appears to be one.

Thank You.
 
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dpa said:
Hi all,

Q. A function takes (x,y) and gives (y,x). Is this function injective?

For any function to be injective, f(x,y)=f(x',y')=>(x,y)=(x',y').
But here, I get,
(y,x)=(y',x')
How can I show the function is injective?

Right so far. Can you conclude (x,y) = (x',y') from that?
 
the ordered pairs are equal means that we can write y=y' and x=x' which in tern mean that
(x,y)=(x',y')

Is this fine.

Thank You.
 
Yes, that's all there is to it.
 
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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