Question

let A be a 3 X 3 matrix with determinant 11.

Find det(adj(6A) )

Isn't the answer (6A)^2?

Answer 1

@thomaster

Answer 2

@amistre64 help!

Answer 3

adjoint(6A) eh ....

Answer 4

im sure there are thrms that help in this that i have forgotten along time ago

Answer 5

an adjoint is the transpose of a cofactor matrix ... not that that helps out any

Answer 6

Use te fact that for n by n matrix A we have \(\det(adj A)=(\det A)^{n-1}\)

Answer 7

yeah, that does sound more useful :)

Answer 8

do i sub 6A for A?