\(\rm \displaystyle\lim_ {x\rightarrow 1}\left({\frac{\sqrt{1-cos2(x-1)}}{(x-1)}}\right)\)
1
Exists and it equals √2
2
Exists and it equals -√2
3
Does not exist because (x - 1) → 1
4
Does not exist because the left hand limit is not equal to the right hand limit.