If can never be
-1
-0.5
0
1
As learnt in
Relation between AM, GM and HM of two positive numbers -
- wherein
Inequality of the three given means.
now
Option 1)
-1
This solution is incorrect
Option 2)
-0.5
This solution is incorrect
Option 3)
0
This solution is incorrect
Option 4)
1
This solution is correct