ThmDex – An index of mathematical definitions, results, and conjectures.
Real square matrix invertible iff transpose is
Formulation 0
Let $A \in \mathbb{R}^{N \times N}$ be a D6160: Real square matrix such that
(i) $A^T$ is a D5841: Real matrix transpose for $A$
Then the following statements are equivalent
(1) $A$ is an D5871: Invertible real matrix
(2) $A^T$ is an D5871: Invertible real matrix
Proofs
Proof 0
Let $A \in \mathbb{R}^{N \times N}$ be a D6160: Real square matrix such that
(i) $A^T$ is a D5841: Real matrix transpose for $A$
This result is a particular case of R5474: Complex square matrix invertible iff conjugate transpose is. $\square$