The document discusses calculating binomial coefficients without using Pascal's triangle. It begins by stating the formula for calculating binomial coefficients as (n over k)(k factorial) over (n factorial) and proves it using mathematical induction. It then explains how the binomial theorem can be derived from this formula for calculating coefficients. It concludes by providing an example calculation of a binomial coefficient.
8. Calculating Coefficients
without Pascal’s Triangle
1
0
CLHS n
RHSLHS
Proof
1
!
!
!!0
!
n
n
n
n
RHS
!!
!
knk
n
Ck
n
Step 1: Prove true for k = 0
Hence the result is true for k = 0
15. 0integeraniswherefortrueisresulttheAssume:2Step rrk
!!
!
..
rnr
n
Cei r
n
1fortrueisresulttheProve:3Step rk
!1!1
!
.. 1
rnr
n
Cei r
n
Proof
11
1
r
n
r
n
r
n
CCC
r
n
r
n
r
n
CCC
1
1
1
16. 0integeraniswherefortrueisresulttheAssume:2Step rrk
!!
!
..
rnr
n
Cei r
n
1fortrueisresulttheProve:3Step rk
!1!1
!
.. 1
rnr
n
Cei r
n
Proof
11
1
r
n
r
n
r
n
CCC
r
n
r
n
r
n
CCC
1
1
1
!!
!
!!1
!1
rnr
n
rnr
n
17. 0integeraniswherefortrueisresulttheAssume:2Step rrk
!!
!
..
rnr
n
Cei r
n
1fortrueisresulttheProve:3Step rk
!1!1
!
.. 1
rnr
n
Cei r
n
Proof
11
1
r
n
r
n
r
n
CCC
r
n
r
n
r
n
CCC
1
1
1
!!
!
!!1
!1
rnr
n
rnr
n
!!1
1!!1
rnr
rnn
18. 0integeraniswherefortrueisresulttheAssume:2Step rrk
!!
!
..
rnr
n
Cei r
n
1fortrueisresulttheProve:3Step rk
!1!1
!
.. 1
rnr
n
Cei r
n
Proof
11
1
r
n
r
n
r
n
CCC
r
n
r
n
r
n
CCC
1
1
1
!!
!
!!1
!1
rnr
n
rnr
n
!!1
1!!1
rnr
rnn
!!1
11!
rnr
rnn
22.
!!1
11!
rnr
rnn
!!1
!
rnr
rnn
!1!1
!
rnr
n
Hence the result is true for k = r + 1 if it is also true for k = r
23.
!!1
11!
rnr
rnn
!!1
!
rnr
rnn
!1!1
!
rnr
n
Hence the result is true for k = r + 1 if it is also true for k = r
Step 4: Hence the result is true for all positive integral values of n
by induction
26. The Binomial Theorem
n
n
nk
k
nnnnn
xCxCxCxCCx 2
2101
n
k
k
k
n
xC
0
27. The Binomial Theorem
n
n
nk
k
nnnnn
xCxCxCxCCx 2
2101
n
k
k
k
n
xC
0
integerpositiveaisand
!!
!
where n
knk
n
Ck
n
28. The Binomial Theorem
n
n
nk
k
nnnnn
xCxCxCxCCx 2
2101
n
k
k
k
n
xC
0
integerpositiveaisand
!!
!
where n
knk
n
Ck
n
NOTE: there are (n + 1) terms
29. The Binomial Theorem
n
n
nk
k
nnnnn
xCxCxCxCCx 2
2101
n
k
k
k
n
xC
0
integerpositiveaisand
!!
!
where n
knk
n
Ck
n
NOTE: there are (n + 1) terms
This extends to;
n
k
kkn
k
nn
baCba
0
30. The Binomial Theorem
n
n
nk
k
nnnnn
xCxCxCxCCx 2
2101
n
k
k
k
n
xC
0
integerpositiveaisand
!!
!
where n
knk
n
Ck
n
NOTE: there are (n + 1) terms
This extends to;
n
k
kkn
k
nn
baCba
0
4
11
Evaluate.. Cge
31. The Binomial Theorem
n
n
nk
k
nnnnn
xCxCxCxCCx 2
2101
n
k
k
k
n
xC
0
integerpositiveaisand
!!
!
where n
knk
n
Ck
n
NOTE: there are (n + 1) terms
This extends to;
n
k
kkn
k
nn
baCba
0
4
11
Evaluate.. Cge
!7!4
!11
4
11
C
32. The Binomial Theorem
n
n
nk
k
nnnnn
xCxCxCxCCx 2
2101
n
k
k
k
n
xC
0
integerpositiveaisand
!!
!
where n
knk
n
Ck
n
NOTE: there are (n + 1) terms
This extends to;
n
k
kkn
k
nn
baCba
0
4
11
Evaluate.. Cge
!7!4
!11
4
11
C
1234
891011
33. The Binomial Theorem
n
n
nk
k
nnnnn
xCxCxCxCCx 2
2101
n
k
k
k
n
xC
0
integerpositiveaisand
!!
!
where n
knk
n
Ck
n
NOTE: there are (n + 1) terms
This extends to;
n
k
kkn
k
nn
baCba
0
4
11
Evaluate.. Cge
!7!4
!11
4
11
C
1234
891011
34. The Binomial Theorem
n
n
nk
k
nnnnn
xCxCxCxCCx 2
2101
n
k
k
k
n
xC
0
integerpositiveaisand
!!
!
where n
knk
n
Ck
n
NOTE: there are (n + 1) terms
This extends to;
n
k
kkn
k
nn
baCba
0
4
11
Evaluate.. Cge
!7!4
!11
4
11
C
1234
891011
3
35. The Binomial Theorem
n
n
nk
k
nnnnn
xCxCxCxCCx 2
2101
n
k
k
k
n
xC
0
integerpositiveaisand
!!
!
where n
knk
n
Ck
n
NOTE: there are (n + 1) terms
This extends to;
n
k
kkn
k
nn
baCba
0
4
11
Evaluate.. Cge
!7!4
!11
4
11
C
1234
891011
330
3
38. (ii) Find the value of n so that;
85a) CC nn
kn
n
k
n
CC
39. (ii) Find the value of n so that;
85a) CC nn
kn
n
k
n
CC
13
58
n
n
40. (ii) Find the value of n so that;
85a) CC nn
kn
n
k
n
CC
13
58
n
n
8
20
87b) CCC nn
41. (ii) Find the value of n so that;
85a) CC nn
kn
n
k
n
CC
13
58
n
n
8
20
87b) CCC nn
k
n
k
n
k
n
CCC
1
11
42. (ii) Find the value of n so that;
85a) CC nn
kn
n
k
n
CC
13
58
n
n
8
20
87b) CCC nn
k
n
k
n
k
n
CCC
1
11
19n
43. (ii) Find the value of n so that;
85a) CC nn
kn
n
k
n
CC
13
58
n
n
8
20
87b) CCC nn
k
n
k
n
k
n
CCC
1
11
19n
11
3
5ofexpansionin the5th termtheFind
b
aiii
44. (ii) Find the value of n so that;
85a) CC nn
kn
n
k
n
CC
13
58
n
n
8
20
87b) CCC nn
k
n
k
n
k
n
CCC
1
11
19n
11
3
5ofexpansionin the5th termtheFind
b
aiii
k
k
kk
b
aCT
3
5
1111
1
45. (ii) Find the value of n so that;
85a) CC nn
kn
n
k
n
CC
13
58
n
n
8
20
87b) CCC nn
k
n
k
n
k
n
CCC
1
11
19n
11
3
5ofexpansionin the5th termtheFind
b
aiii
k
k
kk
b
aCT
3
5
1111
1
4
7
4
11
5
3
5
b
aCT
46. (ii) Find the value of n so that;
85a) CC nn
kn
n
k
n
CC
13
58
n
n
8
20
87b) CCC nn
k
n
k
n
k
n
CCC
1
11
19n
11
3
5ofexpansionin the5th termtheFind
b
aiii
k
k
kk
b
aCT
3
5
1111
1
4
7
4
11
5
3
5
b
aCT
4
747
4
11
35
b
aC
47. (ii) Find the value of n so that;
85a) CC nn
kn
n
k
n
CC
13
58
n
n
8
20
87b) CCC nn
k
n
k
n
k
n
CCC
1
11
19n
11
3
5ofexpansionin the5th termtheFind
b
aiii
k
k
kk
b
aCT
3
5
1111
1
4
7
4
11
5
3
5
b
aCT
4
747
4
11
35
b
aC
unsimplified
48. (ii) Find the value of n so that;
85a) CC nn
kn
n
k
n
CC
13
58
n
n
8
20
87b) CCC nn
k
n
k
n
k
n
CCC
1
11
19n
11
3
5ofexpansionin the5th termtheFind
b
aiii
k
k
kk
b
aCT
3
5
1111
1
4
7
4
11
5
3
5
b
aCT
4
747
4
11
35
b
aC
unsimplified
4
7
8178125330
b
a
49. (ii) Find the value of n so that;
85a) CC nn
kn
n
k
n
CC
13
58
n
n
8
20
87b) CCC nn
k
n
k
n
k
n
CCC
1
11
19n
11
3
5ofexpansionin the5th termtheFind
b
aiii
k
k
kk
b
aCT
3
5
1111
1
4
7
4
11
5
3
5
b
aCT
4
747
4
11
35
b
aC
unsimplified
4
7
8178125330
b
a
4
7
2088281250
b
a