#Need help with matrices 2x2 transformations

63 messages · Page 1 of 1 (latest)

terse orchidBOT
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hard crag
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hey im the guy who asked what u meant, sorry i dont know about using matrices to transform graphs

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im sure theres someone else who can help you out

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good luck

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i know about matrices but i didnt know u could use it to show graphical transformations

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sorry

lavish vale
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You'd need to write down the points

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Say for point C you have [0 1] vertical

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And, when multiplied by something, we gwt C'

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Well, how would you solve the matrix equation

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When you have XA=A'

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We'd want to move the A to the other side. How would we do that?

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We dont have division defined correct

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So what you do is you multiply with the inverse on the right

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$XAA^{-1}$

livid aspenBOT
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Ephesians 2:8-9

lavish vale
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That way we get XI

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And anything multiplied with the identity matrix is itself so we just get X

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$XAA^{-1}=A'A^{-1}$

livid aspenBOT
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Ephesians 2:8-9

lavish vale
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And what we do to one side, we also do to the other

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$X=A'A^{-1}$ is what you're looking for

livid aspenBOT
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Ephesians 2:8-9

lavish vale
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Then you'd need to find the inverse and multiply them

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To find X

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@cerulean spear did I lose you somewhere?

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So

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Hehe

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Wdym

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A is just the coordinate

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Which can be represented as a 2x1 matrix

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And A' is the resulting point, also a 2x1 matrix

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I think that's the way to work out this problem. Let me know if it works

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Yeah

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Yeah, I overlooked that

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Give me a moment

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$\begin{bmatrix}
a & b\
c & d
\end{bmatrix}\begin{bmatrix}
1\
0
\end{bmatrix} = \begin{bmatrix}
2\
0
\end{bmatrix}$

livid aspenBOT
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Ephesians 2:8-9

lavish vale
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So a×1+b×0=2 right?

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@cerulean spear

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What else can you get from there

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a is 2 that's correct

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c is not 2

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c×1+d×0=0

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Where are you from č

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Lol

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Its a letter in my language, that's why I ask

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Anyways č=0 correct

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We have a and c

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Lets try to find the other two using another point

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Cuz you cant figure it out from this one. The other two could be anything cuz theyre multiplied by 0

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Try point C for example

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Yeah

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Looks good

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And you can check if you multiply it by B whether you get B'

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Looks good

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So it's simpler than what I initally imagined

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But hey you learned an additional technique when working with square matrices

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Worked out all in all

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Yep

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Yeah the transform goes first

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Yw