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Am I correct to say that this matrix $C$ cannot be found $$C\times\left(\begin{array}{cc} 9 & 1\\ 4 & 6\\ 3 & 4\end{array}\right) = \left(\begin{array}{cc}9&1\\4 & 6\\ 3&4\end{array}\right)$$

because the columns does not match the rows?

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    http://en.wikipedia.org/wiki/Matrix_multiplication#Matrix_product_.28two_matrices.292012-04-28

1 Answers 1

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In this case, C must be a 3x3 matrix.

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    how does that work? 3X3 x2X3 != 2X32012-04-28
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    3x3 X 3x2 = 3x22012-04-28
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    Try $C=I_3$ and multiplying it out for yourself. Not positive it's the only solution, but it should work.2012-04-28
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    Oops! :/ Should have read that better2012-04-28
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    @Fatz: **first** the number of rows, *then* the number of columns. Your two matrices, other than $C$, are both $3\times 2$.2012-04-28
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    Yup got it, thanks :)2012-04-28