A tetrahedron
is given such that
. Let
, where
is an arbitrary point in space. Compute the least value of
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A tetrahedron $ABCD$ is given such that $AD = BC = a; AC = BD = b; AB\cdot CD = c^2$. Let $f(P) = AP + BP + CP + DP$, where $P$ is an arbitrary point in space. Compute the least value of $f(P).$
Školjka