MATH 166 SCW Lecture 19 Work for Examples 3, 4, and 5

Example 3

Find some partial sums of the series
∞
∑
k=1
1
1+
2
k
, for increasing values of n:
TableFormTable10^n,Sum
1.
1+k^2
,{k,1,10^n},{n,1,7},TableHeadings->None,"n","
S
n
=
n
∑
k=1
1
1+
2
k
"
Out[]//TableForm=
n
S
n
=
n
∑
k=1
1
1+
2
k
10
0.981793
100
1.06672
1000
1.07567
10000
1.07657
100000
1.07666
1000000
1.07667
10000000
1.07667+0.
Check if Mathematica can find the actual sum S for this series, i.e
S=
∞
∑
k=1
1
1+
2
k
.
Sum
1
1+k^2
,{k,1,∞}
Out[]=
1
2
(-1+πCoth[π])
N[%]
Out[]=
1.07667

Example 4

Sum[1/k^5,{k,1,23}]
Out[]=
1106136860583472631494090651392248539192679773
1066745227156578837062475058249339864272076800
N[%]
Out[]=
1.03693

Example 5

TableFormTablen,DecimalFormSum
1.
5
k
,{k,1,n}+
1
4
4
(n+1)
,7,DecimalFormSum
1.
5
k
,{k,1,n}+
1
4
4
n
,7,DecimalForm12*Sum
1.
5
k
,{k,1,n}+
1
4
4
n
+Sum
1.
5
k
,{k,1,n}+
1
4
4
(n+1)
,7,DecimalForm12*Sum
1.
5
k
,{k,1,n}+
1
4
4
n
-Sum
1.
5
k
,{k,1,n}+
1
4
4
(n+1)
,7,{n,1,15},TableHeadings->{None,{n,"Lower Est.","Upper Est.","Average Est.","Error Bound"}}
Out[]//TableForm=
n
Lower Est.
Upper Est.
Average Est.
Error Bound
1
1.015625
1.25
1.132813
0.1171875
2
1.034336
1.046875
1.040606
0.00626929
3
1.036342
1.038452
1.037397
0.001054929
4
1.036742
1.037318
1.03703
0.0002882813
5
1.036855
1.037062
1.036958
0.0001035494
6
1.036895
1.036983
1.036939
0.00004438898
7
1.036911
1.036954
1.036932
0.00002154406
8
1.036919
1.036941
1.03693
0.0000114656
9
1.036922
1.036935
1.036929
0.000006551974
10
1.036924
1.036932
1.036928
0.000003962332
11
1.036926
1.036931
1.036928
0.000002509505
12
1.036926
1.03693
1.036928
0.000001651566
13
1.036927
1.036929
1.036928
0.000001122745
14
1.036927
1.036929
1.036928
0.0000007847168
15
1.036927
1.036928
1.036928
0.0000005617872