Question
Let 
find a so that f may be derivable at x =1.
Solution
Here, f(1) = 1+a
(here h < 0 
1+h < 1)
(here h >0 
1 + h > 1)
Since f is derivable at x =1
∴ Lf'(1) = Rf'(1)
1 = 2a 
