OG 11 - Coordinate Geometry

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OG 11 - Coordinate Geometry

by albertrahul » Wed Jul 09, 2008 5:32 am
In the rectangular coordinate system, are the points (r,s) and (u,v) equidistant from the origin?

(1) r + s = 1
(2) u = 1 - r and v = 1 - s

Please explain your solution. Thanks!

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by augusto » Wed Jul 09, 2008 6:34 am
I might be tired after working all day, but I think it's E.

Because if you put both statements together you end up with 3 equations and 4 variables.


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Re: OG 11 - Coordinate Geometry

by olika » Wed Jul 09, 2008 6:55 am
The answer is C, right?

I solved it just by picking numbers. Not very safe method, i know...

:D

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Re: OG 11 - Coordinate Geometry

by olika » Wed Jul 09, 2008 7:06 am
I think you can solve it like this.

We know that r+s=1, so we can conclude that r=1-s and s=1-r.

Then we have u=1-r and v=1-s. We can substitute like this u=1-(1-s), which means u=s. The same way, v=r. Thus, we can conclude that two points equidistant from (0,0)

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by aj5105 » Sat Oct 04, 2008 6:56 am
imo -- taking numbers and solving is quick and hassle free..

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by kris610 » Sat Oct 04, 2008 7:43 am
I think it would be C.

A and B together tell you that r=v, u=s => The two points are (v,s) (s,v).

Both the points are at a distance of sqrt(v^2+s^2) from the origin.