In the cube \( ABCDEFGH \) with \( S_{AC} \) being the midpoint of the diagonal \( AC \), let \( \varphi \) be the angle between the line \( EG \) and the line \( GS_{AC} \). Choose the correct expression for \( \varphi \):
In the cube \( ABCDEFGH \), let \( S_{FG} \) be the midpoint of the edge \( FG \). Find the angle between the lines \( BS_{FG} \) and \( BF \). Round the result to two decimal places.
In the cube \( ABCDEFGH \) with \( S_{AC} \) being the midpoint of the diagonal \( AC \), let \( \varphi \) be the angle between the line \( ES_{AC} \) and the bottom face \( ABCD \). Choose the correct expression for \( \varphi \).
The picture shows the triangle \( KLM \) with indicated vectors \( \overrightarrow{a} \), \( \overrightarrow{b} \), \( \overrightarrow{c} \) in a coordinate system. What are the vector coordinates \( \overrightarrow{b} \)? Express \( \overrightarrow{b} \) as a linear combination of \( \overrightarrow{a} \) and \( \overrightarrow{c} \).
Given the vectors \( \overrightarrow{a} \), \( \overrightarrow{b} \), \( \overrightarrow{c} \) shown in the picture, express a vector \( \overrightarrow{b} \) as a linear combination of vectors \( \overrightarrow{a} \) and \( \overrightarrow{c} \).