1103024305

SubArea: 
Points and Vectors
Level: 
A
Project ID: 
1103024305
Accepted: 
1
Clonable: 
0
Easy: 
0
In a tetrahedron \( ABCD \), let \( \vec{b} = \overrightarrow{AB} \), \( \vec{c} = \overrightarrow{AC} \), \( \vec{d} = \overrightarrow{AD} \), \( \vec{e} = \overrightarrow{AE} \) and \( \vec{f} = \overrightarrow{DE} \). Further let \( E \) be the midpoint of \( BC \). Express vectors \( \vec{e} \) and \( \vec{f} \) as a linear combination of vectors \( \vec{b} \), \( \vec{c} \), \( \vec{d} \).
\( \vec{e} = \frac12\vec{b} + \frac12\vec{c};\ \vec{f} = \frac12\vec{b} + \frac12\vec{c} - \vec{d} \)
\( \vec{e} = \frac12\vec{b} + \frac12\vec{d};\ \vec{f} = \vec{b} + \vec{c} + \vec{d} \)
\( \vec{e} = \vec{b} + \vec{c};\ \vec{f} =\frac12\vec{b} + \frac12\vec{c} - \vec{d} \)
\( \vec{e} = \frac12\vec{b} + \frac12\vec{c};\ \vec{f} = \frac12\vec{b} + \frac12\vec{c} + \vec{d} \)