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