Problem:
Find the projection of the first vector onto the second:
$\left(
\begin{array}{c}
 2 \\
 -1 \\
 -1 \\
 -3 \\
\end{array}
\right)$,
$\left(
\begin{array}{c}
 0 \\
 1 \\
 -3 \\
 1 \\
\end{array}
\right)$.
Answer:
$\left\{0,-\frac{1}{11},\frac{3}{11},-\frac{1}{11}\right\}$
{'source': 'AMPS', 'file': 'amps/mathematica/linear_algebra/vector_angles_and_projections/36101.txt'}