olemus
ruutmaatriks I, mille
peadiagonaali iga elemendi väärtus on 1,
ja iga muu elemendi väärtus on 0

Oxford Languages:
a square matrix in which all the elements of the principal diagonal are ones and all other elements are zeros

omadused
iga maatriksi A korral kehtib AI = IA = A

ülevaateid
https://en.wikipedia.org/wiki/Identity_matrix

https://study.com/academy/lesson/identity-matrix-definition-properties.html

http://mathworld.wolfram.com/IdentityMatrix.html

https://www.onlinemathlearning.com/identity-matrix.html