i
t
e
r
a
t
i
o
n
s
t
e
p
0
1
2
3
4
5
6
f
(
x
)
I
t
e
r
a
t
i
o
n
=
0
x
_
n
=
-
1
.
f
(
x
_
n
)
=
3
.
