How can I determine if a set of vectors forms a subspace?

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To determine if a set of vectors forms a subspace, one must check if linear combinations of the vectors can generate all elements in the target space. The discussion revolves around using the equation e*A + f*B + g*C to express a matrix with specific entries. The term VecR(A, B, C) is suggested to refer to a spanning set, although its notation is not commonly found in linear algebra textbooks. The solution approach involves setting the linear combination equal to the target matrix and solving for the coefficients. The expected outcome is a proportional relationship rather than a specific numerical solution.
phy
Hi guys. I need some help with question #5 from my assignment. If someone can just tell me how to get the question started, it would be great. Thanks :smile:

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If A, B and C generate U then e*A +f*B + g*C generates every element in U (in this case that a b c d matrix). Of course you know this already seeing as you did the rest of those. What does VecR(A, B, C) mean? No linear alg. book I've ever worked with uses that notation.
 
I'm not 100% sure on this either but somebody who I spoke to said that VecR(A, B, C) is just a spanning set. I couldn't find it in my textbook either.

So would I just set e*A +f*B + g*C equal to the matrix with entries a b c d and then solve?
 
phy said:
I'm not 100% sure on this either but somebody who I spoke to said that VecR(A, B, C) is just a spanning set. I couldn't find it in my textbook either.

So would I just set e*A +f*B + g*C equal to the matrix with entries a b c d and then solve?

Ok that's what I figured. Yeah and you should get some sort of proportionality between the four and not a numerical answer once you solve it out.
 
Alrightie I'll do that. Thanks a lot =)
 
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