1) Координаты векторов:
\(\overrightarrow{AC} = (3-2; 2-(-1)) = (1; 3)\)
\(\overrightarrow{AD} = (-3-2; 1-(-1)) = (-5; 2)\)
2) Модули векторов:
\(|\overrightarrow{AC}| = \sqrt{1^2 + 3^2} = \sqrt{10}\)
\(|\overrightarrow{AD}| = \sqrt{(-5)^2 + 2^2} = \sqrt{29}\)
3) Координаты вектора \(\overrightarrow{EF}\):
\(3\overrightarrow{AC} = (3; 9)\)
\(2\overrightarrow{AD} = (-10; 4)\)
\(\overrightarrow{EF} = (3 - (-10); 9 - 4) = (13; 5)\)
4) Скалярное произведение векторов \(\overrightarrow{AC}\) и \(\overrightarrow{AD}\):
\(\overrightarrow{AC} \cdot \overrightarrow{AD} = (1 \cdot -5) + (3 \cdot 2) = -5 + 6 = 1\)
5) Косинус угла между векторами \(\overrightarrow{AC}\) и \(\overrightarrow{AD}\):
\(\cos(\angle(\overrightarrow{AC}, \overrightarrow{AD})) = \frac{\overrightarrow{AC} \cdot \overrightarrow{AD}}{|\overrightarrow{AC}| \cdot |\overrightarrow{AD}|} = \frac{1}{\sqrt{10} \cdot \sqrt{29}} = \frac{1}{\sqrt{290}} \approx 0.055\)