Is $BB^{\top}+ c I$ an invertible matrix?
141286
When is $\mathbf{X}^{T}\mathbf{X}+\lambda\mathbf{I}$ invertible?
120407
Is every noninvertible matrix a zero divisor?
78307
Under what conditions is $AA^T$ invertible?
33355
Proving that matrix in equation is invertible
85845
Matrix with zeros on diagonal and ones in other places is invertible
15202
the root of $N$th transpose matrix
125021
Inverse of an invertible upper triangular matrix of order 3
130268
How to prove that a nilpotent matrix is not invertible?
80623
Must $S$ be a unitary matrix?
152665
$A^TA+I$ is always invertible?
32108
$ a\in \Bbb Z_n$ is invertible $\,\Rightarrow\gcd (a,n) =1$
33559
Product or sum of invertible matrix give an invertible matrix?
129564
Show that $A$ is an invertible matrix if $\left(A+I\right)^3=0$ and find $A^{-1}$
146099
Why is this true: The only orthogonal projection that is also unitary from $\Bbb C^n$ to $\Bbb C^n$ is the identity
125889
Determinant of rank-one perturbations of (invertible) matrices
67990
Commutativity of matrix and its transpose
70723
Why are nonsquare matrices not invertible?