Trong không gian Oxyz , cho ba vectơ OA = ( 1 ; − 2 ; 7 ) ; vectơ OB = ( 5 ; 6 ; 3 ) ; vectơ AC = ( − 4 ; 7 ; 10 ) ; vectơ BD = ( − 10 ; 0 ; 8 ) . Tìm tọa độ các điểm A , B , C , D
Ta có:
\[\begin{array}{l}\overrightarrow {OA} = \left( {1\;;\; - 2\;;\;7} \right) \Rightarrow A\left( {1\;;\; - 2\;;\;7} \right).\\\overrightarrow {OB} = \left( {5\;;6\;;\;3} \right) \Rightarrow B\left( {5\;;6\;;\;3} \right).\end{array}\]
\[\begin{array}{l}\;\overrightarrow {AC} = \left( { - 4\;;\;7\;;\;10} \right) \Leftrightarrow \left\{ \begin{array}{l}{x_C} - 1 = - 4\\{y_C} + 2 = 7\\{z_C} - 7 = 10\end{array} \right. \Leftrightarrow \;\left\{ \begin{array}{l}{x_C} = - 3\\{y_C} = 5\\{z_C} = 17\end{array} \right. \Rightarrow C\left( { - 3\;;\;5\;;\;17} \right).\\\overrightarrow {BD} = \left( { - 10\;;0\;;\;8} \right) \Leftrightarrow \left\{ \begin{array}{l}{x_D} - 5 = - 10\\{y_D} - 6 = 0\\{z_D} - 3 = 8\end{array} \right. \Leftrightarrow \;\left\{ \begin{array}{l}{x_D} = - 5\\{y_D} = 6\\{z_D} = 11\end{array} \right. \Rightarrow D\left( { - 5\;;\;6\;;\;11} \right).\end{array}\]