② : (ot)(81,82,*,8n)=o(t(81,82,**en))= 0((c1,82,,8n)B) = 0(81,82,*,8n)B=(81,62,.,8n)(AB)OT在基1,82,8下的矩阵为AB③: (ko)(81,82,*,8n)=((ko)(s),.,(ko)(cn)=(ko(c),..,ko(c.))= k(o(c),.*,o(on))= ko(81,82,*,8n) = k(81,82,,8n)A(81,82,,8.)(kA)ko在基3,62,,8n下的矩阵为kA.87.3线性变换的矩阵A§7.3 线性变换的矩阵 ② (         )( 1 2 1 2 , , , , , , n n ) = ( ( )) =     (( 1 2 , , , n ) B) =     ( 1 2 , , , n )B ( )( ) 1 2 , , , =    n AB ∴  在基    1 2 , , , n 下的矩阵为AB. ③ (k k k         )( 1 2 1 , , , , , n n ) = (( )( ) ( )( )) = ( k k     ( 1 ), , ( n )) = k (    ( 1 ), , ( n )) = k    ( 1 2 , , , n ) = k A (   1 2 , , , n ) ( )( ) 1 2 , , , n =    kA ∴ k 在基    1 2 , , , n 下的矩阵为 kA