$\tiny{s6.12.4.35}$
$\textrm{Find the volume of theparallelepiped with adjacent edges
$PQ, PR$, and $PS$.}$
\begin{align*}\displaystyle
P(2,0,-1),& \, Q(4,1,0), \, R(3.-1.1), S(2,-2,2)\\
\end{align*}
ok I know the problem is basically solved with
\begin{align*}\displaystyle...