please help i need to do this a.s.a.p

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- Oct 21st 2008, 04:57 AM #1

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## Problem

Demonstrate , using the definition of the dot product, that the length of the vectors a and b are equal if an only if the diagonals of the quadrilateral OAQB are orthogonal.

__A Q__

__O B__

its meant to be a rhombus

Hint: Use that if (OA-OB) is perependicualr to (OA+OB) then OA = OB and vice versa.

P.S dont tell me the answer just need some help of what to do help much appreciated

- Oct 21st 2008, 07:27 AM #2

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- Oct 21st 2008, 11:54 AM #3

- Oct 21st 2008, 11:59 AM #4

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