If f (2) = 4 and f' (2) = 4, then equals.

   Lt         x - [x] , where k is an integer, is equal to
 x→ k+

    Lt       [x]  is equal to.
 x→ 2^-

  then       Lt   f(x) is
                                                             x → ∞

 is equal to.

                 = 0  , [x]=0

Where [x] denotes the greatest integer ≤x, then   f(x) equals