compute the following. If an answer does not exist, enter DNE.

Question

Let A= [ 5 ]

[ 1 ]

[ 5 ]

If possible, compute the following.

A^TA=

AA^T=

Answer 1

A^TA = [5 1 5][5] = [25+1+25] = [51]

[1]

[5]

AA^T= [5][5 1 5] = [25 5 25]

[1] [5 1 5]

[5] [25 5 25]