... )13 2 13 1 30 2 1 1 2 00xx y zy Ix y zz = ỡ - + + ỡ = = ù ù = - ị - - ớ ớ ù ù + + + = = ợ ợ. D ctd nờniquaI0 ,25 ( ) Ã ,d D lnnht ( ) Ã0, 9 0d d D = D ^0 ,25 dcúvtcp ... ữ ố ứ ố ứ uur uur0 ,25 ( )4 2AB = - uuurlvtptcat BC ( )pt : 2 0 2BC x y C c c ị - = ị . ( ) ( ) ( ) ( ) ( ) ( ) 2 2 2 2000 2 5, 2 2 4 . Ta cú pt: 2 2 4 2 5 2 2448CcAB BC c c ... 6 2 3 84 2 z iiz z i i - - ị - = - - = - - + =0 ,25 t ( ) ( )( ) ( ) ( )' , 1 3 6 2 3 8 3 6 2 3 3 8z x yi x y x yi i i x y y x i = + ẻ ị + - - + = + - + + - = Ă ( ) ( ) 2 23...