Linear Algebra for Computer Science

Question

Find matrices C and D, both having rank greater such that the product of CD has rank zero?

Answer 1

0 0 ... 1

0 0 ... 1

...

0 0 1

and

1 1 .... 1

0 0 ... 0

...

0 0 0

For N-2

0 1 and 1 1

0 1 0 0

The rank of C and D are 1 but the rank of the product is zero