... Tacú thddngchngminhrngúl1tronghaigiaoim cangthngiquatõm mtcuvtrungim caAB. 28 2 Vớd15: Chomtcu ( S ) : ( x - 1) + ( y - + z2 = vmtphng (a ) : x - y + z + =0 ) Vitptmpnmtrongmp (a) , iquaim A( ... ( 0a),khi útacú: ur uuu r uu uur r ộu1 IM ự ộu2INự ỷ ỷ d ( I , D1 ) = d ( I ,D )= R = ur uu ,trong M (11 ) , N( 2 r ) u1 u2 Vớd9: Chobaim A(10 ) , B ( 01 ) , C( 01 Vitptmtcucúbỏn kớnh nhnhtmtipxỳcvi...