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 one year ago
Let {u,v,w} be a base for the vector space V. Determine if {u1,u2,u3} is a basis for V, where u1=u+v3w; u2=u+3vw and u3=v+w.
 one year ago
Let {u,v,w} be a base for the vector space V. Determine if {u1,u2,u3} is a basis for V, where u1=u+v3w; u2=u+3vw and u3=v+w.

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blockcolder
 one year ago
Best ResponseYou've already chosen the best response.0Given that any vector \(\vec{v}\in V\) can be written as \(\vec{v}=c_1u+c_2v+c_3w\), can \(\vec{v}\) be also written as \(\vec{v}=d_1u_1+d_2u_2+d_3u_3\)?

ybarrap
 one year ago
Best ResponseYou've already chosen the best response.0$$ Ax=b\\ \begin{bmatrix} 1&1 &3 \\ 1&3 &1 \\ 0& 1 & 1 \end{bmatrix} \begin{bmatrix} u\\ v\\ w \end{bmatrix} = \begin{bmatrix} u_1\\ u_2\\ u_3 \end{bmatrix}\\$$ Rowreducing A shows that \(u_1,u_2\) and \(u_3\) only fill a 2dimensional space. $$ \begin{bmatrix} 1&1 &3 \\ 0&1 &1 \\ 0& 0 & 0 \end{bmatrix} $$ Since {u,v,w} is a basis for V, they are independent and fill a 3dimensional space. Therefore, it is not possible for {u1,u2,u3} to be a basis for V.

AJBB
 one year ago
Best ResponseYou've already chosen the best response.0I have that the matrix is [1 1 0X] [131Y] [311] which I reduced and gave me 0=2x+1/2y+z I just don't know if it is correct.

ybarrap
 one year ago
Best ResponseYou've already chosen the best response.0I'm not following exactly. What i tried to show above was that the two basis could not span the same space because the second spans a smaller space than V.

AJBB
 one year ago
Best ResponseYou've already chosen the best response.0I have the matrix you showed, except that your rows are my columns and am trying to solve for a general vector (x,y,z) to what space it generates and then determine if it is a basis for V.

Loser66
 one year ago
Best ResponseYou've already chosen the best response.0I know what you don't understand, you see, you said \({u_1,u_2,u_3}\), it means you should expand them as column vectors. I mean dw:1379732186029:dw

AJBB
 one year ago
Best ResponseYou've already chosen the best response.0So I would have a matriz like this: dw:1379732284595:dw?

Loser66
 one year ago
Best ResponseYou've already chosen the best response.0and make it in the form of rref

ybarrap
 one year ago
Best ResponseYou've already chosen the best response.0That's right, now use @Loser66 's suggestion and rowreduce

Loser66
 one year ago
Best ResponseYou've already chosen the best response.0do you know how to make it in that form?

AJBB
 one year ago
Best ResponseYou've already chosen the best response.0Yes, I'm trying to do it right now.

Loser66
 one year ago
Best ResponseYou've already chosen the best response.0use your prof's terminology. Each of them has his own way to represent the process. And most of them ...hehehe.... tooooo stubborn to accept others' ways

Loser66
 one year ago
Best ResponseYou've already chosen the best response.0let see, It 's so late here. just post, if I can, I will.

Loser66
 one year ago
Best ResponseYou've already chosen the best response.0not that form, something like this dw:1379733034406:dw

Loser66
 one year ago
Best ResponseYou've already chosen the best response.0when you see 1 zero row in the system like this, it means the system is linear dependent.

Loser66
 one year ago
Best ResponseYou've already chosen the best response.0and if it is DEPENDENT system, it is not a base for R^3 which needs 3 INDEPENDENT vector base.

AJBB
 one year ago
Best ResponseYou've already chosen the best response.0Ok, got it! So I wouldn't need to find the determinant to see if it is a base?

Loser66
 one year ago
Best ResponseYou've already chosen the best response.0you can do it also. it's a good idea when you have a square matrix like this. det A =0, so it 's linear dependent> not the base

Loser66
 one year ago
Best ResponseYou've already chosen the best response.0because it is general form to do for ANY matrix, that's why they give you this method. You are right when determine it by determinant

AJBB
 one year ago
Best ResponseYou've already chosen the best response.0ok, Thank you! Can you help me out with linear transformations, please?

AJBB
 one year ago
Best ResponseYou've already chosen the best response.0Let T:R3 to R2 be a linear transformation so that T(1,0,1)=(1,1) ; T(1,1,2)=(2,3) and T(1,1,0)=(2,1) Determine T(x,y,z) Prove that T(x,y,z) is a linear transformation. Sorry if the wording is a little weird, I'm translating form Spanish.

Loser66
 one year ago
Best ResponseYou've already chosen the best response.0I am not sure whether my answer is right or wrong because It 's easy to see. They give you that x, y ,z. Is it not that x =(1,0,1) ( first T), y =(1,1,2) ( second T ) and z = (1,1,0) ( the third T). And by calculate determinant of that matrix you have it = 2 therefore it 's linear independent .

AJBB
 one year ago
Best ResponseYou've already chosen the best response.0I don't know either. I think they are asking if it is a linear transformation not independent.I do know it has something to to with general vectors.