Answer
The statement is correct.
Work Step by Step
The matrices $A$ and $B$ are square matrices of order $n$ with
$A B=I$
Therefore,
$|A B|=|I|=1$
Since $|A B|=|A||B|$, then
$|A||B|=1$
This relation indicates that $A$ and $B$ do not equal to zero.
