Can non-square matrices be invertible?
70723
Why are nonsquare matrices not invertible?
146243
Does there exist a matrix $\mathbf{A}\in\mathbb{R}^{3\times3}$ such that $\mathbf{A}^{2}=-\mathbf{I}$?
85845
Matrix with zeros on diagonal and ones in other places is invertible
40517
Determinant of a non-square matrix
75215
Properties of invertible matrices
63475
Is there any connection between a matrix being invertible and being diagonalizable?
143629
Looking for insightful explanation as to why right inverse equals left inverse for square invertible  matrices
91812
Using inverse of transpose matrix to cancel out terms?
75066
If the product of two square matrices is invertible, then both matrices are invertible
125021
Inverse of an invertible upper triangular matrix of order 3
45523
Can the product of two non invertible elements in a ring be invertible?
40222
Matrices that are not diagonal or triangular, whose eigenvalues are the diagonal elements
34820
Transpose Operator is diagonalizable?
33559
Product or sum of invertible matrix give an invertible matrix?
25229
Can any set of $n$ relatively prime elements be extended to an invertible matrix?
131480
Proof that composition of invertible linear transformations is invertible (without determinants)
124149
Inverse of matrix with nonnegative entries