Finding a Basis Subset in (a, b, c, d) for S in R4 | Homework Solution

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Homework Statement


Let S be the form of (a, b,c ,d )in R4, given a not equal to 0. Find the basis that is subset of S.

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The Attempt at a Solution


I got a(1,0,0,0), b(0,1,0,0), c(0,0,1,0), d(0,0,0,1) as basis. a not = 0
But i wasn't sure what the significances of a not = to 0 means

Any help would be appreciated.
Thanks in advance.
 
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It means find four elements of R4 that are linearly independent and all of whose first components are non-zero. That would comprise such a basis.
 
However, the set of all (a, b, c, d) in R4 such that a\ne 0 is NOT a subspace and so does NOT have a basis. Are you sure you have read the problem correctly?
 
I'm thinking the OP may have the problem stated correctly since he/she calls S a set. They just seek a basis for R4 choosing only from that set.
 
Ah! You are right. I misread it. The problem is NOT to find a basis for S but to find a basis for R4 such that the first component of each basis vector is not 0.
I would be inclined to take the "standard" basis and change the first component of each to a simple non-zero number. Then check to see if they are still independent.
 
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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