Hey,
I just finished the quizz 3 and had a question about the first question.
In the correct answer, isn't sin(theta) supposed to have an i on the entire diagonal ? as exp(i theta matrix (x) matrix) = Identity cos(theta) + i matrix (x) matrix sin(theta) ? where (x) means tensor product. So all the sinuses would get an i stuck to them.
Thank you in advance !
