Limit of (1-xy)/(1+xy) as (x,y) approaches (1,-1)

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SUMMARY

The limit of the expression (1-xy)/(1+xy) as (x,y) approaches (1,-1) does not exist. Participants in the discussion confirmed that substituting values such as y=-x and xy=u leads to the limit approaching infinity. This indicates that the limit diverges rather than converges to a finite value. The confusion arises from the interpretation of limits approaching infinity as a non-existent limit.

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Homework Statement


[tex]\frac{lim}{(x,y)->(1,-1)}[/tex] [tex]\frac{1-xy}{1+xy}[/tex]


Homework Equations


none


The Attempt at a Solution


I know from the graph this limit doesn't exist, but I tried subbing y=-x, xy=u, y=-1, x=1, and I always come up with the limit going to infinity. Not sure what I'm doing wrong, but I feel like I'm close.
 
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I'm not sure what your question is. Isn't 'going to infinity' one way that a 'limit doesn't exist'?
 

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