Are these answers I came up with acctually solutions or more just idéas that doesn´t acctually show anything and by "coincidence" happend to have the same numbers as the actual solutions?

Question is:

Look at

It is defined by:

with

=

and

a) Find the limit of the recursive formula.

b)Find the limit of

this one I´m not sure I understand everywhere is suddenly we have and then from k=0 where do I put the 0. Or is it just that the sum from.. ..oh well lets just assume it means from

a: Solution: Since the limit of

=limit

we can write (I think)

this is only satisfied if a = 0. Hence the limit must be 0....hmm book said 0 too, well then something must be right (maybe)

b) Solution:

. Book say 1/2..Wow I must have done something correct, ooor there was a

that magicaly appered