Thread: eignenvalue/trace

1. eignenvalue/trace

if a\in R n*n s.t. a^2=I

find all possible values of an eigenvalue \lambdaof a (without using characteristic polynomial)

show tr(a)=n \Rightarrowa=I

any suggestions, im really stuck anything would help

2. wow i really dont know how to type these questions either i hope this makes some sense at least

3. Hint