Level:
Project ID:
1103024303
Accepted:
1
Clonable:
0
Easy:
0
The picture shows a rectangular cuboid \( ABCDEFGH \) with \( \vec{a} = \overrightarrow{AB} \), \( \vec{b} = \overrightarrow{AD} \), \( \vec{c} = \overrightarrow{AE} \), \( \vec{x} = \overrightarrow{AK} \) and \( \vec{y} = \overrightarrow{AL} \). Point \( K \) is the midpoint of \( FG \) and point \( L \) is the centre of face \( BCGF \). Express vectors \( \vec{x} \) and \( \vec{y} \) as a linear combination of vectors \( \vec{a} \), \( \vec{b} \), \( \vec{c} \).
\( \vec{x} = \vec{a} + \frac12\vec{b} + \vec{c};\ \vec{y} = \vec{a} + \frac12\vec{b} + \frac12\vec{c} \)
\( \vec{x} = \frac12\vec{a} + \vec{b} + \frac12\vec{c};\ \vec{y} = \vec{a} - \frac12\vec{b} + \frac12\vec{c} \)
\( \vec{x} = \vec{a} + \frac12\vec{b} + \frac12\vec{c};\ \vec{y} = \vec{a} - \frac12\vec{b} + \frac12\vec{c} \)
\( \vec{x} = \vec{a} + \frac12\vec{b} + \frac12\vec{c};\ \vec{y} = \frac12\vec{a} + \frac12\vec{b} + \frac12\vec{c} \)