Questions askedCategory: 2568Question about HW2, Section 1.5, Question 58, Part B
Max asked 2 years ago
Max replied 2 years ago

What exactly is this question asking us to do? Are just supposed to just give a matrix $C$ where $AC \neq CA$?

1 Answers
Yu Staff answered 2 years ago

I think Part (b) asks you to find concrete examples of matrices $B$ and $C$ such that $AB=BA$ and $AC\neq CA$. In part (a), you must have obtained a formula for $B$ so that $AB=BA$. Thus if a matrix $C$ does not satisfy the formula, then $AC\neq CA$.

So, you may randomly find a matrix $C$ such that $AC\neq CA$ but part (b) narrows down the possibility.