MA137 Mathematical Analysis
1. Evaluate
1X
n=1
5 ?? 3n
23n .
2. Prove that, for n > 2,
1 +
1
n
n2
>
n2 ?? 1
2
. Deduce that
1X
n=1
1 +
1
n
??n2
converges.
3. Show that
log( 3
2 ) 6
1X
n=1
1
n(2n + 1) 6 1
3 + log( 3
2 ):
4. Let (bn)n2N+ be a bounded sequence. Prove that if
P1
n=1 an is absolutely convergent then
P1
n=1 anbn
is also absolutely convergent.
5. Sketch the graph of f(x) =
p
x; x > 0, and use it, together with relevant calculations, to explain why
2
3N3=2 <
XN
n=1
p
n < 2
3 (N3=2 ?? 1) +
p
N:
6. Find the value of
1X
n=2
1
n3 ?? n
by the telescoping series method.
7. Recall from Question 1 on Examples Sheet 0 that, 8 a; b 2 R,
jabj 6 1
2 (a2 + b2): (1)
(a) Suppose that an > 0 8 n 2 N+ and that
P1
n=1 an < +1. Make appropriate choices of a and b in
(1) to prove that
1X
n=1
p
an
n
< +1:
(b) Provide an example of a sequence (an)n2N+ for which an > 0 8 n 2 N+ and
P1
P n=1 an < +1 but 1
n=1
p
an = +1.
Worked Example
Find the value of
1X
n=1
p
n + 2 ??
p
n p
n(n + 2)
by the telescoping series method.
Solution
p
n + 2 ??
p
n p
n(n + 2)
=
1
p
n
??
1
p
n + 2
. Therefore,
p
3 ??
p
1
p
3
=
1
1
??
1
p
3
p
4 ??
p
2
p
8
=
1
p
2
??
1
p
4
p
5 ??
p
3
p
15
=
1
p
3
??
1
p
5
...
...
p
k + 1 ??
p
k ?? 1 p
(k ?? 1)(k + 1)
=
1
p
k ?? 1
??
1
p
k + 1
p
k + 2 ??
p
k p
k(k + 2)
=
1
p
k
??
1
p
k + 2
:
Therefore,
Xk
n=1
p
n + 2 ??
p
n p
n(n + 2)
= 1 +
1
p
2
??
1
p
k + 1
??
1
p
k + 2
:
It follows that
1X
n=1
p
n + 2 ??
p
n p
n(n + 2)
= lim
k!1
1 +
1
p
2
??
1
p
k + 1
??
1
p
k + 2
= 1 +
1
p
2
:
17
Invitational Speech
This speech will be a three-part speech: the first part is the issue; the second part is your dialogue with the audience and the third part is your summary and your conclusion.
Criteria for the speech: 6-7 minutes for the issues part of the speech; 2-3 minutes for the dialogue and 1-2 minutes for the conclusion. The speech should contain three different sources in it. Only two of the sources may be taken from the Internet. ( "An outline and an annotated bibliography are required for this speech. This is a capstone speech which utilizes the rhetorical concepts.") THIS ALL I NEED.
I need about 5 great slides ppt
Poverty: America’s crippling problem