document.write( "Question 1164529: Suppose A is a square matrix. Prove that there is a symmetric matrix B and a skew-symmetric matrix C such that A = B + C. In other words, any square matrix can be decomposed into a symmetric matrix and a skew-symmetric matrix (Proof Technique DC). \n" ); document.write( "
Algebra.Com's Answer #788930 by ikleyn(52781)\"\" \"About 
You can put this solution on YOUR website!
.
\n" ); document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "For any square matrix A,   \r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "    A = \"%281%2F2%29%2A%28A+%2B+A%5Et%29\" + \"%281%2F2%29%2A%28A+-+A%5Et%29\".     (1)\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "In this decomposition,  \"A%5Et\" is the matrix A \"transposed\".\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "In the decomposition (1), the matrix  B = \"%281%2F2%29%2A%28A+%2B+A%5Et%29\"  is s symmetric matrix,  and  the matrix  C = \"%281%2F2%29%2A%28A+-+A%5Et%29\"\r\n" );
document.write( "\r\n" );
document.write( "is the skew-symmetric matrix.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "So (1) provides a required decomposition.\r\n" );
document.write( "
\r
\n" ); document.write( "\n" ); document.write( "Solved.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "
\n" );