- #1

Yankel

- 395

- 0

Given the following matrix,

\[A=\begin{pmatrix} 2 & 6\\ 1 & a \end{pmatrix}\]

and given that

\[\lambda =0\]

is an eigenvalue of A, I am trying to determine that value of a.

What I did, is to create the characteristic polynomial

\[(\lambda -2)*(\lambda -a)+6=0\]

and given

\[\lambda =0\]

I got that a is -3.

Somehow I am not sure. Is there a way of finding the second eigenvalue before calculating a ?

Thank you !