
Eigenvalues
Hi everyone, I am needing some help. I have the matrix
A= [2 1/2]
.....[1/2 1]
According to my book, the eigenvalue for this is λ1= λ2=3/2 and the eigenvector is
v=[1]
...[1]
However, this is not what I am getting. I'm not seeing where they are getting the 3/2 from. I know the process of finding the eigenvalue because I have successfully solved my other homework problems but this one is stumping me. Can someone show how to get the 3/2 eigenvalue?

by $\displaystyle \det(A\lambda I)=0$
you get the quadratic
$\displaystyle \lambda^23\lambda+ \frac{9}{4}=0$
which factors to be
$\displaystyle \left(\lambda\frac{3}{2}\right)^2=0$
gives $\displaystyle \lambda = \frac{3}{2}$

OH ok I see it...I must have been havin a brain fart. Thanks for your help!