8

Part of 2021 IMC

Problems(1)

IMC 2021 P8: Maximum number of vectors such that for any 3, 2 are orthogonal

Source: IMC 2021 P8

n

be a positive integer. At most how many distinct unit vectors can be selected in

\mathbb{R}^n

such that from any three of them, at least two are orthogonal?

IMC 2021vectorcombinatoricslinear algebra