In this segment we will talk about some theorems
of eigenvalues and eigenvectors so the second
theorem right here saying that if lambda=0
is an eigenvalue 
of a nxn [A] matrix, then [A] is noninvertible
so if you find out that one of the eigenvalues
of the [A] matrix of a square matrix turns
out to be zero just one then the [A] matrix
is noninvertible which is the same as saying
(singular) which is the same as saying its
inverse doesn t exist and so on and so forth
so that s what it is telling you so for example
if somebody says that hey this is my matrix
given to me [A]=5, 6, 2, 3, 5, 9, 2, 1, -7
for this particular matrix if you go through
the process of finding the eigenvalues you
will find that lambda=0 is an eigenvalue youll
find one of the eigenvalues is zero so what
does that mean that means that [A] inverse
does not exist that means that [A] inverse
does not exist or it means that [A] is not
invertible it means [A] is singular it also
means that the det(A)=0 because if [A] inverse
does not exist then we know that for a square
matrix the det of that matrix has to be equal
to zero that s the end of this segment
