Inconsistency pg. 222

[noa-codes]

On page 222, the course reader states that Q_k^T A Q_k = H_k, (or equivalently, A Q_k = Q_k H_k) but in class we showed that Q_k Hk + h{k+1, k} q_{k+1} e_k^T = A Qk. Is there a reason that we drop the q{k+1} term here?

[EricDarve]

I am not sure where you are seeing this in the course reader. Q_k^T A Q_k = H_k is true but A Q_k = Q_k H_k is not. Qk Qk^T is not I.

[noa-codes]

I see, my mistake!