document.write( "Question 307330: Let X, Y and Z be matrices of sizes 2x3, 4x3 and 1x4, respectively. Then the size of (XY)^T(Z)^T (where ^T denotes transpose of a matrix) is (2x1)\r
\n" ); document.write( "\n" ); document.write( "The answer to the question is 2x1, but I don't understand how to get that answer.\r
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "

Algebra.Com's Answer #219931 by jim_thompson5910(35256) $\"\"$ $\"About$

You can put this solution on YOUR website!
I'm assuming you meant to write $\"XY%5ET%2AZ%5ET\"$ \r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "First off, $\"Y%5ET\"$ is a 3x4 matrix (since the transpose flips the rows and columns). So $\"XY%5ET\"$ is a 2x4 matrix since the product of an m x n and an n x r matrix is an m x r matrix. Also, $\"Z%5ET\"$ is a 4x1 matrix (transposes swap rows and columns). So because $\"XY%5ET\"$ is a 2x4 matrix and $\"Z%5ET\"$ is a 4x1 matrix, this means that $\"XY%5ET%2AZ%5ET\"$ is a 2x1 matrix. \n" ); document.write( "

\n" );