Question #68ef5

1 Answer
Dec 17, 2017

See below.

Explanation:

If #lambda# is an eigenvalue of #B# then

#Bu = lambda u# but #B= V^-1 A V# and then

#V^-1 A V x = lambda u = lambda V^-1 Vu# or

#A(Vu)=lambda(Vu)# then #w = Vu# is an associated eigenvector to #A#

Now the eigenvalues are the values which obey

#"det"(B-lambdaI) = 0# Taking instead

#"det"(V^-1AV-lambda I) = "det"(V^-1(A-lambda I) V)#

but #det(U V) = "det"(U)"det"(V)# so #"det"(V^-1)"det"(V) = 1#

and finally

#"det"(V^-1AV-lambda I) ="det"(A-lambda I)=0# and then

#lambda# is eigenvalue for #B# and #A#