Question

Give a formula for (ABx)^T, where x is a vector and A and B are matrices of appropriate sizes.

Answer 1

Do you understand the question better?

Answer 2

I don't know if they want you to find an example or come up with a general solution.

Answer 3

I think that it is asking for a general example because it sounds like there are multiple ways to do this. But then again I'm not sure

Answer 4

Why not just let A and B be identity matrices and let x be some vector?

Answer 5

the only other thing I can think to do is... \[
(ABx)^T=b\\
ABx = b^T\\
x = (AB)^{-1}b^T\\
x = B^{-1}A^{-1}b^T
\]

Answer 6

Does that go back to the identity matrices? or is that talking about inverses?

Answer 7

The \(^{-1}\) means inverse.

Answer 8

thanks!