A is orthogonal if the A^{-1} = A^{T}.
Thus, AA^{T} = I.
However, is the statement A is orthogonal equivalent to A^{2}=I.
I don't think the statements are equivalent, but it comes from a test. Thus, I'd hope the test is correct.
Homework Statement
Given X=ZU+Y
where
(i) U,X,Y, and Z are random variables
(ii) U~N(0,1)
(iii) U is independent of Z and Y
(iv) f(z) = \frac{3}{4} z2 if 1 \leq z \leq 2 , f(z)=0 otherwise
(v) fY|Z=z(y) = ze-zy (i.e. Y depends conditionally on...
Given a discrete time signal x[n] that has a DTFT (which exists in the mean square convergence or in the uniform convergence sense), how can we tell if the signal x[n] converges absolutely?
I know the following:
x[n] is absolutely summable <=> X(e^{j \omega}) converges uniformly (i.e...