Consider the series
Find an expression for an.
an
==
M8
an = (x-5)³+
(x-5)6 (x-5)9
(x-5) 12
+
+
+...
2.2!
4.3!
8.4!
1-10
In the summation formula n starts at n = no. What is your starting index no?
no=
(Note that because the validity of either of your answers depends on the other, if you enter only one, both will be marked wrong.)