xm sin(1 / x) , x is not equal to 0
Show that the function ƒ(x) = is
0 , x = 0
(i) differentialble at x = 0, if m1
(ii) continous but not differentiable at x = 0, if 0
(iii) neither continous nor differentiable, if m ≤ 0
Here is the link for the similar answer to your query.