Linear Algebra matrix linear transformation

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The discussion revolves around finding the coordinate matrix [T]EE for a linear transformation T from V = P2 to W = P2, defined by a specific polynomial transformation. Participants are attempting to apply T to the basis vectors e1(t), e2(t), and e3(t) to derive the matrix representation. There is confusion regarding the application of the transformation and the correct interpretation of the basis vectors. Clarifications are made about the use of the transformation definition and the relationship between the basis vectors in both spaces. The conversation emphasizes the importance of correctly applying the transformation to each basis vector to construct the matrix.
Rifscape
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Homework Statement


Consider the linear transformation T from
V = P2
to
W = P2
given by
T(a0 + a1t + a2t2) = (−4a0 + 2a1 + 3a2) + (2a0 + 3a1 + 3a2)t + (−2a0 + 4a1 + 3a2)t^2
Let E = (e1, e2, e3) be the ordered basis in P2 given by
e1(t) = 1, e2(t) = t, e3(t) = t^2
Find the coordinate matrix [T]EE of T relative to the ordered basis E used in both V and W, that is, fill in the blanks below: (Any entry that is a fraction should be entered as a proper fraction, i.e. as either x/y or -x/y where x and y are positive integers with no factors in common.)
T(e1(t)) = _e1(t) + _ e2(t) + _e3(t)
T(e2(t)) = _e1(t) + _e2(t) + _e3(t)
T(e3(t)) = _e1(t) + _e2(t) + _e3(t)
and therefore :
[T]EE = the combined matrix of the coefficients of the above three equations.

Sorry for the poor formatting

Homework Equations


No idea

The Attempt at a Solution


I have no idea
I have no idea how to do this, if someone can give me a step by step solution so that I can understand each step and process I would appreciate it greatly.
Thanks for your help.
 
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Rifscape said:

Homework Statement


Consider the linear transformation T from
V = P2
to
W = P2
given by
T(a0 + a1t + a2t2) = (−4a0 + 2a1 + 3a2) + (2a0 + 3a1 + 3a2)t + (−2a0 + 4a1 + 3a2)t^2
You mean T(a0+ a1t+ a2t^2) on the left, right?

Let E = (e1, e2, e3) be the ordered basis in P2 given by
e1(t) = 1, e2(t) = t, e3(t) = t^2
Find the coordinate matrix [T]EE of T relative to the ordered basis E used in both V and W, that is, fill in the blanks below: (Any entry that is a fraction should be entered as a proper fraction, i.e. as either x/y or -x/y where x and y are positive integers with no factors in common.)
T(e1(t)) = _e1(t) + _ e2(t) + _e3(t)
T(e2(t)) = _e1(t) + _e2(t) + _e3(t)
T(e3(t)) = _e1(t) + _e2(t) + _e3(t)
and therefore :
[T]EE = the combined matrix of the coefficients of the above three equations.

Sorry for the poor formatting

Homework Equations


No idea

The Attempt at a Solution


I have no idea
I have no idea how to do this, if someone can give me a step by step solution so that I can understand each step and process I would appreciate it greatly.
Thanks for your help.
To find the matrix corresponding to a linear transformation in a given ordered basis, apply that linear transformation to each basis vector in turn and write the result as a linear combination of those basis vectors. The coefficients give a column of the basis. For example, to apply the linear transformation two the first basis vector, T(e1), note that e1= 1+ 0t+ 0t^2. That is, a0= 1, a1= 0, and a2= 0. Since T is defined by "T(a0 + a1t + a2t2) = (−4a0 + 2a1 + 3a2) + (2a0 + 3a1 + 3a2)t + (−2a0 + 4a1 + 3a2)t^2". T(1+ 0t+ 0t^2)= (-4(1)+ 2(0)+ 3(0))+ (2(1)+ 3(0)+ 3(0))t+ (-2(1)+ 4(0)+ 3(0))t^2= -4+ 2t- 2t^2. The first column of the matrix is \begin{pmatrix}-4 \\ 2 \\ -2\end{pmatrix}.

Now do the same to the second and third basis vectors.
 
T(f1(t)) = f1(t) + f2(t) + f3(t)
When I put in the first one which is f1(t) = 1, so it would be 1 + 0t + 0t^2. So when I plug it in, I should get (2(1) + 0 + 0) + (2(1) + 0 + 0)t + (-2(1) + 0 + 0)t^2
= (2,2,-2) However when I put this in it is wrong, does it have something to do with how f2(t) is now 1 + t, and f3(t) is now 1 + t + t^2?
T(f2(t)) = f1(t) + f2(t) + f3(t)
T(f3(t)) = f1(t) + f2(t) + f3(t)
 
Rifscape said:
T(f1(t)) = f1(t) + f2(t) + f3(t)
When I put in the first one which is f1(t) = 1, so it would be 1 + 0t + 0t^2. So when I plug it in, I should get (2(1) + 0 + 0) + (2(1) + 0 + 0)t + (-2(1) + 0 + 0)t^2
= (2,2,-2) However when I put this in it is wrong, does it have something to do with how f2(t) is now 1 + t, and f3(t) is now 1 + t + t^2?
T(f2(t)) = f1(t) + f2(t) + f3(t)
T(f3(t)) = f1(t) + f2(t) + f3(t)

So, you have ##T(e_1) = 2 e_1 + 2 e_2 - 2 e_3##. Why do you think this is wrong?
 
When I enter the numbers in it says it is wrong, except the - 2 at the end which is right. I feel like I am doing something wrong since f2(t) is now 1+t.
 
Rifscape said:
T(f1(t)) = f1(t) + f2(t) + f3(t)
When I put in the first one which is f1(t) = 1, so it would be 1 + 0t + 0t^2. So when I plug it in, I should get (2(1) + 0 + 0) + (2(1) + 0 + 0)t + (-2(1) + 0 + 0)t^2
= (2,2,-2) However when I put this in it is wrong, does it have something to do with how f2(t) is now 1 + t, and f3(t) is now 1 + t + t^2?
T(f2(t)) = f1(t) + f2(t) + f3(t)
T(f3(t)) = f1(t) + f2(t) + f3(t)
Where did f1, f2, and f3 come from? The same basis, i.e., ##e_1, e_2,## and ##e_3## is used in both V and W. In this problem V and W are the same spaces.
You aren't using the definition of the transformation, which I've copied below.
##T(a_0 + a_1t + a_2t^2) = (−4a_0 + 2a_1 + 3a_2) + (2a_0 + 3a_1 + 3a_2)t + (−2a_0 + 4a_1 + 3a_2)t^2##
Use this definition to see what T does to ##e_1## (HallsOfIvy already did this one), ##e_2##, and ##e_3##.
 
No sorry I didn't clarify. I finished the last question, this is a completely new question. I solved the previous question with hall of ivys help. However when I apply the same strategy to this question I cannot solve it. This question has f instead of e. Sorry for the confusion
 
Rifscape said:
No sorry I didn't clarify. I finished the last question, this is a completely new question.
I solved the previous question with hall of ivys help. However when I apply the same strategy to this question I cannot solve it. This question has f instead of e. Sorry for the confusion
Then you should start a new thread, with the complete problem statement of the new problem.
 

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