If detA =3 for some nxn matrix, what is det(A^T A)?

782 Views Asked by At

If $\det(A) =3$ for some $n\times n$ matrix, what is $\det(A^{T} A)$? I know that $\det (A)=\det(A^T)$ but combined?

1

There are 1 best solutions below

1
On

$\newcommand{\mat}[1]{\mathbf{#1}}$ $$ \det (\mat A^\intercal \mat A) = \det \mat{A}^\intercal \det \mat A = (\det \mat A)^2 $$