olemus
ruutmaatriksi A pöördmaatriks
on maatriks B, mis rahuldab tingimust AB = BA = I,
kus I on ühikmaatriks

Wiktionary:
inverse matrix
of a matrix A, another matrix B such that A multiplied by B and B multiplied by A both equal the identity matrix

ülevaateid
http://www.mathwords.com/i/inverse_of_a_matrix.htm

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

http://www.purplemath.com/modules/mtrxinvr.htm

https://en.wikipedia.org/wiki/Invertible_matrix

näiteid
https://www.wikihow.com/Find-the-Inverse-of-a-3x3-Matrix

https://people.richland.edu/james/lecture/m116/matrices/inverses.html