\[\boxed{\mathbf{1039.ОК\ ГДЗ - домашка\ на}\ 5}\]
\[Рисунок\ по\ условию\ задачи:\]
\[\mathbf{Дано:}\]
\[ABCD - квадрат;\]
\[AC \cap DB = O.\]
\[\mathbf{Найти:}\]
\[угол\ между\ векторами.\]
\[\mathbf{Решение.}\]
\[\textbf{а)}\ \left( \widehat{\overrightarrow{\text{AB}};\overrightarrow{\text{AC}}} \right) = 45{^\circ};\]
\[\textbf{б)}\ \left( \widehat{\overrightarrow{\text{AB}};\overrightarrow{\text{DA}}} \right) = 90{^\circ};\]
\[\textbf{в)}\ \left( \widehat{\overrightarrow{\text{OA}};\overrightarrow{\text{OB}}} \right) = 90{^\circ};\]
\[\textbf{г)}\ \left( \widehat{\overrightarrow{\text{AO}};\overrightarrow{\text{OB}}} \right) = 90{^\circ};\]
\[\textbf{д)}\ \left( \widehat{\overrightarrow{\text{OA}};\overrightarrow{\text{OC}}} \right) = 180{^\circ};\]
\[\textbf{е)}\ \left( \widehat{\overrightarrow{\text{AC}};\overrightarrow{\text{BD}}} \right) = 90{^\circ};\]
\[\textbf{ж)}\ \left( \widehat{\overrightarrow{\text{AD}};\overrightarrow{\text{DB}}} \right) = 135{^\circ};\]
\[\textbf{з)}\ \left( \widehat{\overrightarrow{\text{AO}};\overrightarrow{\text{OC}}} \right) = 0{^\circ}.\]
\[\boxed{\mathbf{1039.еуроки - ответы\ на\ пятёрку}}\]
\[\mathbf{Решение\ задачи\ дано\ }\]
\[\mathbf{в\ учебнике.}\]