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1. Exercise 7.2. Let A =
0
1. Show that AB = BA.
2. Suppose we can find a matrix C and functions f and g such that A = fCB = gC. Show that all eigenvectors of C must be multiples of e. (So the Jordan canonical form of C has a single Jordan block.)
3. Show that it is impossible to find a matrix C and functions f and g such that A = fC, B = gC. Hint: Check rank of A and B.
4. Show that if AA2 = BB2 such that A = AA2, B = BB2, and A, B = BA for i = 1, 2, then this is the trivial Kronecker tensor decomposition. I.e., we must have A, B to be some scalar multiples of A, B for some i. (So this commutative behavior is different from any commutative behavior we talked about in class.)
5. Is it possible to find X such that A, B are both in Jordan canonical form? Hint: consider the kernel of A and B^2.
6. Find X such that X - BX is in Jordan canonical form while X - 1AX is upper triangular.