How to Calculate T(2, -1, 1) Using Given Linear Transformations?

vanitymdl
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Homework Statement


Let T: R3 → R3 be a linear transformation such that T(1, 1, 1) = (1, 0, –1), T(0, – 1, 2) = (–3, 3, –1), and T(1, 0, 1) = (1, 1, 0). Find the following expression. (Enter each vector as a comma-separated list of its components.)

what is T(2, –1, 1)?


The Attempt at a Solution


So what i did was 2T(1, 1, 1)-T(0, – 1, 2)+T(1, 0, 1)
then this can be rewritten as 2(1, 0, –1)-(–3, 3, –1)+(1, 1, 0) so once I did that I got (6,-2,-1), but that is obviously the wrong answer and I don't know why.
 
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Well, your linear combination to obtain T(2,-1,1) doesn't work out, because the middle component ends up being 3, not -1.
 
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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