A/|a|=b/|b|=(ab)/|ab|= 1, where y = 3；;

2.if a

A/| A | = B/| B | =- 1, (ab)/|ab|= 1, then y =-1;

3. If A and B have different numbers, then: A/| A |+B/| B | = 0, and (AB)/| AB | =- 1, then Y =- 1.

Then the set of values of y is: {- 1, 3}