題組內容

1. (20%) True or False. In each case, answer T if the statement is always true and F otherwise. In the case of a false statement, explain why or give an example to show that the statement is not always true.

(h) If {u1, u2, ..., uk} is an orthonormal set of vectors in R^n and U = (u1, u2, ..., uk), then UUT = In (the n × n identity matrix).