Fermi
·
Concept Library
·
Courses
·
Books
·
Problems
·
Simulations
·
Math Wiki
·
High School
Fermi
›
Problems
Mathematics
Mathematics
Problem
For the series
∑
n
=
1
∞
n
(
x
+
1
)
n
3
n
\displaystyle \sum_{n=1}^{\infty} \dfrac{n\,(x+1)^{n}}{3^{n}}
n
=
1
∑
∞
3
n
n
(
x
+
1
)
n
, determine the interval of convergence. a)
[
−
4
,
2
]
[-4,\,2]
[
−
4
,
2
]
b)
(
−
3
,
3
)
(-3,\,3)
(
−
3
,
3
)
c)
(
−
4
,
2
)
(-4,\,2)
(
−
4
,
2
)
d)
[
−
4
,
2
)
[-4,\,2)
[
−
4
,
2
)
Browse the problem library