Is There a Rational Point Not Equidistant from Any Two Lattice Points?

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SUMMARY

The discussion centers on the mathematical problem of identifying a rational point Q=(r,s) that is not equidistant from any two lattice points, defined as points with integer coordinates. The user explores various geometric and algebraic methods, including circle geometries and perpendicular bisectors, but finds no unifying solution. The analysis reveals that for rational coordinates r=a/b and s=c/d, point Q lies on the line defined by the equation y=(bc/ad)x. The user concludes that points T=(ad,-bc) and U=(-ad,bc) are equidistant from Q, indicating that such a point Q cannot exist under the given conditions.

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  • Understanding of rational numbers and their representation as fractions.
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  • Knowledge of basic geometric concepts, including lines and perpendicular bisectors.
  • Proficiency in algebraic manipulation and solving equations.
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Mathematicians, geometry enthusiasts, and students studying algebraic geometry or rational number theory will benefit from this discussion.

hermes7
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Hello all,
Could someone help me out with this problem? I tried using circle geometries, perpendicular bisectors, and some more pure algebra. Nothing has been "unifying." Here is the problem:
Is it possible to have a point Q=(r,s), where r and s are rational, where the point Q is not equidistant from ANY two lattice points? where a lattice point is a point of integer x and y coordinates.
Thank you in advance!
 
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This is for nonzero cases only, zero cases one can pretty quickly come up with equidistant points.

I may have screwed up some algebra in here but I'm confident the framework will work:


For any rational r and s for some integers a,b,c,d it is true that: r=a/b and s=c/d

It's pretty obvious Q lies on the line xb/a=yd/c

or:
y=(bc/ad)x

O=(0,0) is another point that lies on that line.

Taking the negative recipricol of the line we find the perpendicular line:

y=-ad/bc(x)

of which these two integer solutions can be found (there are of course, an infinite number of integer solutions):

T=(ad,-bc) and U=(-ad,bc)

TOQ and TUQ both form congruent triangles with the hypotenuse being TQ and UQ, and thus T and U are equidistant from Q
 

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