LinAlg - Due today (Linear independence)

eiktmywib
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Homework Statement


A=[-2
-7
-1]

B=[-2
-4
-3]

C=[0
6
-4]

Determine whether or not the three vectors listed above are linearly independent or linearly dependent.
I have determined that they are linearly DEPENDENT.

If they are linearly dependent, determine a non-trivial linear relation - (a non-trivial relation is three numbers which are not all three zero.) otherwise, if the vectors are linearly independent, enter 0's for the coefficients, since that relationship always holds.


Homework Equations


none, sorry

The Attempt at a Solution


I have put the vectors into a matrix and solved it... but then I got something strange, and everytime I do it... I always get different answers. I have determined that they are linearly dependent though.
 
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please help... I have no idea what to do =(
 
You want to solve aA+bB+cC=0. If you equate the components you get three equations in the three unknowns. The first one is -2a-2b=0. What are the others? If you know they are linearly dependent you should expect to get lots of solutions. Your first one says a=-b. I would substitute that into the other equations.
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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