Index of matrices problem with rules and properties | Mathematics | Page 1

amber topaz Sep 12, 2024, 9:47 AM

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wraith shadowBOT Sep 12, 2024, 9:47 AM

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amber topaz

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amber topaz Sep 12, 2024, 9:47 AM

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my problem is that the solution is not defined , but to me that doesnt make sense:

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1st- i put The t on all elements

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actual right equation

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so, here my response

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1st put all in () ^t

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BA^t -2c^tA

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but this is wrong

amber topaz Sep 12, 2024, 9:56 AM

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amber topaz 1st- i put The t on all elements

in the solutions they dont do this

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dunno why

kind nimbus Sep 12, 2024, 10:35 AM

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amber topaz in the solutions they dont do this

yes that expression is not defined

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you're subtracting and 3x2 matrix from a 3x3 matrix. With how you add/subtract matrices, it should be evident why you cant do that

amber topaz Sep 12, 2024, 11:50 AM

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yuh but i thought it was all multiplied

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and like

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-2c * a

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a *-2c

kind nimbus Sep 12, 2024, 2:39 PM

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amber topaz -2c * a

Yes, there's CA^T

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That's 3x3 times a 3x2

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Which is 3x2

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Likewise B^TA is 3x2 and 2x3, which is 3x3

amber topaz Sep 12, 2024, 5:46 PM

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yeah and they different

kind nimbus Sep 12, 2024, 5:46 PM

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Yep

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Hence why it's not defined

amber topaz Sep 12, 2024, 5:47 PM

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i didnt get it

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because i dont know how you are supposed to know when its a subtraction or one times the other

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in these

kind nimbus Sep 12, 2024, 5:48 PM

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Is 2x multiplying 2 and x or subtracting them?

amber topaz Sep 12, 2024, 5:48 PM

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what do you mean

kind nimbus Sep 12, 2024, 5:48 PM

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Go back to high school algebra

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Is 2x multiplying 2 and x?

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Or subtracting them?

amber topaz Sep 12, 2024, 5:49 PM

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yup

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ehh i get it

kind nimbus Sep 12, 2024, 5:49 PM

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Since you said you can't tell the difference between multiplication and subtraction

amber topaz Sep 12, 2024, 5:49 PM

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but they dont really put the signs here

kind nimbus Sep 12, 2024, 5:49 PM

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kind nimbus Is 2x multiplying 2 and x?

.

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You know this is multiplication despite no explicit sign

amber topaz Sep 12, 2024, 5:50 PM

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hmmm now

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i get it yeah

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not ignore the subtraction

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if its there

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its a subtraction

kind nimbus Sep 12, 2024, 5:51 PM

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Just like high school

amber topaz Sep 12, 2024, 5:51 PM

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hmmm

kind nimbus Sep 12, 2024, 5:51 PM

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Juxtaposition of symbols refers to multiplication of some sort.

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Unless told otherwise

amber topaz Sep 12, 2024, 5:53 PM

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thankssss

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i'll probably be here all night asking linear algebra questions

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so if could help me just with some of them id be really glad

amber topaz Sep 12, 2024, 5:54 PM

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kind nimbus Juxtaposition of symbols refers to multiplication of some sort.

thanks

red charmBOT Sep 12, 2024, 5:54 PM

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@amber topaz has given 1 rep to @kind nimbus

amber topaz Sep 12, 2024, 5:54 PM

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+close

#Index of matrices problem with rules and properties