My Math Forum Matrix as a product of elementary matrices

 Linear Algebra Linear Algebra Math Forum

 January 29th, 2011, 01:07 PM #1 Newbie   Joined: Jan 2011 Posts: 1 Thanks: 0 Matrix as a product of elementary matrices Hey everyone I need to make this matrix as products of elementary matrices $\begin{bmatrix} -3 & 1 \\ 2 & 2 \end{bmatrix}$ I cannot seem to get the answer, I've done it multiple times and this is what I get for the answer: $\begin{bmatrix} -3 & 0 \\ 0 & 1 \end{bmatrix}$ $\begin{bmatrix} 1 & 0 \\ 2 & 1 \end{bmatrix}$ $\begin{bmatrix} 1 & 0 \\ 0 & \frac4{3} \end{bmatrix}$ $\begin{bmatrix} 1 & -\frac{1}3 \\ 0 & 1 \end{bmatrix}$ Can someone please help figure out what I am doing wrong. Thanks
 February 1st, 2011, 09:39 AM #2 Senior Member   Joined: Nov 2010 Posts: 502 Thanks: 0 Re: Matrix as a product of elementary matrices I'm sorry, but what does it mean to make it the product of elementary matrices? It looks pretty elementary to me, unless that's a particular term.
 February 1st, 2011, 10:14 AM #3 Senior Member   Joined: Feb 2009 From: Adelaide, Australia Posts: 1,519 Thanks: 3 Re: Matrix as a product of elementary matrices This much is correct: $\begin{bmatrix}1 & 0 \\ 0 & \frac43\end{bmatrix}\cdot\begin{bmatrix} 1 & -\frac13 \\ 0 & 1\end{bmatrix}=\begin{bmatrix}1 & -\frac13 \\ 0 & \frac43\end{bmatrix}$ Now what you want is to add the first row to the second row, so premultiply by $\begin{bmatrix} 1 & 0 \\ 1 & 1\end{bmatrix}$, and finish by premultiplying with row multiplications.

 Tags elementary, matrices, matrix, product

 Thread Tools Display Modes Linear Mode

 Similar Threads Thread Thread Starter Forum Replies Last Post rnck Linear Algebra 4 August 16th, 2012 08:37 AM maximus101 Algebra 0 March 14th, 2011 09:41 AM remeday86 Linear Algebra 1 June 25th, 2010 10:12 PM tinynerdi Linear Algebra 1 March 4th, 2010 07:06 PM wannabe1 Linear Algebra 2 February 2nd, 2010 09:57 PM

 Contact - Home - Forums - Cryptocurrency Forum - Top