\[\boxed{\mathbf{559.}ОК\ ГДЗ\ –\ домашка\ на\ 5}\]
\[Рисунок\ к\ задаче:157.\]
\[Дано:\]
\[\text{ABCD}A_{1}B_{1}C_{1}D_{1} -\]
\[параллелепипед;\]
\[\text{M\ }и\ K - середины\ B_{1}C_{1}\ и\ A_{1}D_{1}.\]
\[Найти:\]
\[пары\ векторов.\]
\[Решение.\]
\[\textbf{а)}\ Сонаправленные\ векторы:\]
\[\overrightarrow{D_{1}A_{1}} \uparrow \uparrow \overrightarrow{C_{1}B_{1}};\ \ \overrightarrow{D_{1}A_{1}} \uparrow \uparrow \overrightarrow{\text{CB}};\ \ \]
\[\overrightarrow{C_{1}B_{1}} \uparrow \uparrow \overrightarrow{\text{CB}}\text{.\ }\]
\[D_{1}A_{1} \parallel C_{1}B_{1} \parallel CB\ как\ ребра\ \]
\[параллелепипеда:\]
\[D_{1}K = C_{1}\text{M\ \ }и\ \ D_{1}D = C_{1}C;\]
\[\mathrm{\Delta}D_{1}DK = \mathrm{\Delta}C_{1}CM;\]
\[\angle D_{1}DK = \angle C_{1}\text{CM.}\]
\[Отсюда:\ \]
\[\overrightarrow{\text{DK}} \uparrow \uparrow \overrightarrow{\text{CM}}.\]
\[\textbf{б)}\ Противоположно\ \]
\[направленные\ векторы:\]
\[\overrightarrow{A_{1}A} \uparrow \downarrow \overrightarrow{CC_{1}};\ \ \overrightarrow{\text{CD}} \uparrow \downarrow \overrightarrow{\text{AB}};\ \ \]
\[\overrightarrow{D_{1}A_{1}} \uparrow \downarrow \overrightarrow{\text{AD}};\ \ \]
\[\overrightarrow{C_{1}B_{1}} \uparrow \downarrow \overrightarrow{\text{AD}};\ \ \ \overrightarrow{\text{CB}} \uparrow \downarrow \overrightarrow{\text{AD}};\]
\[\textbf{в)}\ Равные\ вектора\ \]
\[(сонаправлены\ и\ равны\ по\ модулю):\]
\[\overrightarrow{D_{1}A_{1}} = \overrightarrow{C_{1}B1\ } = \overrightarrow{\text{CB}};\ \ \]
\[\overrightarrow{\text{CM}} = \overrightarrow{\text{DK}}.\]