A particularly nasty delta-epsilon

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SUMMARY

The discussion focuses on proving the continuity of the function f(x,y) = x/y without using the quotients of limits theorem. Participants suggest starting with a point (x0, y0) where y0 is not equal to zero and manipulating the expression |(x/y) - (x0/y0)|. The key approach involves rewriting the numerator to facilitate showing that it can be made small while ensuring the denominator remains non-zero.

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Homework Statement



Prove the function f(x,y) = x/y is continuous.
As an added stipulation, the quotients of limits theorem may not be used.

Homework Equations


The Attempt at a Solution


I have absolutely no idea how to go about this one. I can't even get a start on the scratchwork... Can anyone give me any hints to push me along the right way?
 
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Here's a start. Pick (x0,y0) with y0 not equal zero.

\left |\frac x y - \frac {x_0} {y_0}\right |= \left |\frac{y_0x-x_0y}{yy_0}\right |

Now subtract and add y0x0 in the numerator and see if you can make the fraction small. You have to get the numerator small and keep the denominator away from 0.
 

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