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?