Fermi
·
Concept Library
·
Courses
·
Books
·
Problems
·
Simulations
·
Math Wiki
·
High School
Fermi
›
Problems
Lebl-Basic-Analysis-I
· Problem 6.2.9
Sequences of Functions
Mathematics · l1-norm-pointwise-convergence
Problem
Find a sequence
{
f
n
}
n
=
1
∞
\{f_n\}_{n=1}^\infty
{
f
n
}
n
=
1
∞
of Riemann integrable functions on
[
0
,
1
]
[0,1]
[
0
,
1
]
converging pointwise to
0
0
0
, but such that
lim
n
→
∞
∥
f
n
∥
L
1
\displaystyle\lim_{n\to\infty} \|f_n\|_{L^1}
n
→
∞
lim
∥
f
n
∥
L
1
does not exist (is
∞
\infty
∞
), where
∥
f
∥
L
1
:
=
∫
0
1
∣
f
(
x
)
∣
d
x
\|f\|_{L^1} \mathrel{:=} \displaystyle\int_0^1 |f(x)|\, dx
∥
f
∥
L
1
:=
∫
0
1
∣
f
(
x
)
∣
d
x
.
Related theory
Series Convergence Tests And Absolute Convergence
Browse the problem library