ax1+a2X2+…+anxn =(X1,x2,…,Xn） a21+022+…ta2mxn anlX1+an2X2+…+amxn =(x…xn〉 21 02 02n an nn Xn x"Ax              + + + + + + + + + = n n n n n n n n n n a x a x a x a x a x a x a x a x a x x x x      1 1 2 2 2 1 1 2 2 2 2 1 1 1 1 2 2 1 1 2 ( , , , ) ( ) 11 12 1 1 21 22 2 2 1 2 1 2 n n n n n nn n a a a x a a a x x x x a a a x          =          T = x Ax