Have you tried anything? Like writing down the formula for the derivative at 0:
Does that give you any ideas.
(I assume that your "and (0, 0) is a point" means that (0, 0) is a point in the graph of y= f(x)- in other words, that f(0)= 0.)
i) Determine "a" values for which f is differentiable at 0 and determine the f'(o) values.
ii) Determine "a" values for which f' is continuous at 0.
iii) Determine "a" values for which f"(0) exists and determine its value(s).