Let A be a 4 X 2 matrix, A = $\displaystyle \begin{bmatrix}-1&0 \\ 0 & 1 \\ 1&2\\ 2&1 \end{bmatrix}$

Is there a 2X4 matrix such that $\displaystyle BA = I_2$?

A little clarifications would be nice, totally dont understand this question at all.

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- Oct 19th 2008, 06:39 PMp00ndawgMatrix Inverses, help plz
Let A be a 4 X 2 matrix, A = $\displaystyle \begin{bmatrix}-1&0 \\ 0 & 1 \\ 1&2\\ 2&1 \end{bmatrix}$

Is there a 2X4 matrix such that $\displaystyle BA = I_2$?

A little clarifications would be nice, totally dont understand this question at all. - Oct 19th 2008, 07:00 PMmr fantastic
- Oct 19th 2008, 11:55 PMSimonM
- Oct 20th 2008, 12:23 AMmr fantastic
- Oct 20th 2008, 12:29 AMbumcheekcity
- Oct 20th 2008, 12:39 AMmr fantastic
Yes, I did misunderstand the question.

One way to do it would be to assume that $\displaystyle B = \begin{bmatrix} a& b & c & d \\ e &f & g &h \end{bmatrix}$, do the multiplication, equate entries and solve the resulting four linear equations (infinite number of solutions). - Oct 20th 2008, 12:40 AMSimonM
- Oct 20th 2008, 12:45 AMmr fantastic
- Oct 20th 2008, 12:46 AMSimonM
- Oct 20th 2008, 02:51 AMCaptainBlack
- Oct 20th 2008, 04:52 AMp00ndawg
ahhh I see thank you guys.