As x->0+0,
|x|->0, cosx -> 1-0; so [cosx]-> 0
As x->0-0,
|x|->0, cosx -> 1-0; so [cosx]-> 0
so, limit exists and is equal to zero.
As x->0+0,
|x|->0, cosx -> 1-0; so [cosx]-> 0
As x->0-0,
|x|->0, cosx -> 1-0; so [cosx]-> 0
so, limit exists and is equal to zero.