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It's a little more complicated than: """It's funny because the whole discussion only exists because there is no division operator in "matrix math"."""

Matrices in general (insert caveats on size here) form a ring, but not a division ring (https://en.wikipedia.org/wiki/Division_ring). This means that not all (square) matrices will have a multiplicative inverse. This is why we often restrict to things like GL(n), the group of non-singular square matrices of size n.

Furthermore when you say "scalars", they have multiplicative inverses because they're elements of a field (and sometimes the inverse might be a pain like if you're in a number field or something).

This isn't even getting into the Moore-Penrose pseudoinverse (https://en.wikipedia.org/wiki/Moore–Penrose_pseudoinverse) or linear operators or so on, but I'll let someone else shout about algebra.




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