Home » Archimedes archive » Acorn User » AU 1997-01 B.adf » Regulars » StarInfo/Allen/!Ignotum/Formulae/Formulae/Seri

StarInfo/Allen/!Ignotum/Formulae/Formulae/Seri

This website contains an archive of files for the Acorn Electron, BBC Micro, Acorn Archimedes, Commodore 16 and Commodore 64 computers, which Dominic Ford has rescued from his private collection of floppy disks and cassettes.

Some of these files were originally commercial releases in the 1980s and 1990s, but they are now widely available online. I assume that copyright over them is no longer being asserted. If you own the copyright and would like files to be removed, please contact me.

Tape/disk: Home » Archimedes archive » Acorn User » AU 1997-01 B.adf » Regulars
Filename: StarInfo/Allen/!Ignotum/Formulae/Formulae/Seri
Read OK:
File size: 05FF bytes
Load address: 0000
Exec address: 0000
File contents
# Maths > Series

# New entries should take the form of:
#     Formula
#     Note 1
#     Note 2
#     Note 3
#     Note 4
#     Note 5
#     Formula
#     Note 1
#     And so on...
# To fit snugly into the window, each line should be no longer
# than 42 characters.
# There is a limit of 25 formulas per topic.

# Any notes should be made here, at the beginning and should
# be preceeded by a hash (#).

nth term=a+(n-1)d
For an arithmetic progression, eg 1 3 5 7
9 etc.
a=starting number (eg 1)
d=common difference (eg 2)

S<n>=(n/2)(2a+(n-1)d)
For an arithmetic progression, eg 1 3 5 7
9 etc.
S<n>=sum of the numbers up to term n.
a=starting number (eg 1)
d=common difference (eg 2)
nth term=ar^(n-1)
For a geometric progression, eg 1 2 4 8 16
a=starting number (eg 1)
r=common ratio (eg 2)


S<n>=a(1-r^n)/(1-r)
For a geometric progression, eg 1 2 4 8 16
S<n>=sum of the numbers up to term n.
a=starting number (eg 1)
r=common ratio (eg 2)

S<i>=a/(1-r)
For a geometric progression, when |r|<1,
eg 1 1/2 1/4 1/8 1/16
S<i>=sum of terms to infinity
a=starting number (eg 1)
r=common ratio (eg �)
e=(1/0!)+(1/1!)+(1/2!)+(1/3!)+(1/4!)...
This is one way of calculating e (2.718),
where a! is the factorial of a:
a(a-1)(a-2)(a-3).. until a-n=1
Note: 0!=1

(1+x)^n=1+[nx]+[n(n-1)x�/2!]+...
Known as the power series, for expansion
of the bracket (1+x)^n where n is any real
number (positive, negative, integer and
non-integer).













































































































00000000  23 20 4d 61 74 68 73 20  3e 20 53 65 72 69 65 73  |# Maths > Series|
00000010  0a 0a 23 20 4e 65 77 20  65 6e 74 72 69 65 73 20  |..# New entries |
00000020  73 68 6f 75 6c 64 20 74  61 6b 65 20 74 68 65 20  |should take the |
00000030  66 6f 72 6d 20 6f 66 3a  0a 23 20 20 20 20 20 46  |form of:.#     F|
00000040  6f 72 6d 75 6c 61 0a 23  20 20 20 20 20 4e 6f 74  |ormula.#     Not|
00000050  65 20 31 0a 23 20 20 20  20 20 4e 6f 74 65 20 32  |e 1.#     Note 2|
00000060  0a 23 20 20 20 20 20 4e  6f 74 65 20 33 0a 23 20  |.#     Note 3.# |
00000070  20 20 20 20 4e 6f 74 65  20 34 0a 23 20 20 20 20  |    Note 4.#    |
00000080  20 4e 6f 74 65 20 35 0a  23 20 20 20 20 20 46 6f  | Note 5.#     Fo|
00000090  72 6d 75 6c 61 0a 23 20  20 20 20 20 4e 6f 74 65  |rmula.#     Note|
000000a0  20 31 0a 23 20 20 20 20  20 41 6e 64 20 73 6f 20  | 1.#     And so |
000000b0  6f 6e 2e 2e 2e 0a 23 20  54 6f 20 66 69 74 20 73  |on....# To fit s|
000000c0  6e 75 67 6c 79 20 69 6e  74 6f 20 74 68 65 20 77  |nugly into the w|
000000d0  69 6e 64 6f 77 2c 20 65  61 63 68 20 6c 69 6e 65  |indow, each line|
000000e0  20 73 68 6f 75 6c 64 20  62 65 20 6e 6f 20 6c 6f  | should be no lo|
000000f0  6e 67 65 72 0a 23 20 74  68 61 6e 20 34 32 20 63  |nger.# than 42 c|
00000100  68 61 72 61 63 74 65 72  73 2e 0a 23 20 54 68 65  |haracters..# The|
00000110  72 65 20 69 73 20 61 20  6c 69 6d 69 74 20 6f 66  |re is a limit of|
00000120  20 32 35 20 66 6f 72 6d  75 6c 61 73 20 70 65 72  | 25 formulas per|
00000130  20 74 6f 70 69 63 2e 0a  0a 23 20 41 6e 79 20 6e  | topic...# Any n|
00000140  6f 74 65 73 20 73 68 6f  75 6c 64 20 62 65 20 6d  |otes should be m|
00000150  61 64 65 20 68 65 72 65  2c 20 61 74 20 74 68 65  |ade here, at the|
00000160  20 62 65 67 69 6e 6e 69  6e 67 20 61 6e 64 20 73  | beginning and s|
00000170  68 6f 75 6c 64 0a 23 20  62 65 20 70 72 65 63 65  |hould.# be prece|
00000180  65 64 65 64 20 62 79 20  61 20 68 61 73 68 20 28  |eded by a hash (|
00000190  23 29 2e 0a 0a 6e 74 68  20 74 65 72 6d 3d 61 2b  |#)...nth term=a+|
000001a0  28 6e 2d 31 29 64 0a 46  6f 72 20 61 6e 20 61 72  |(n-1)d.For an ar|
000001b0  69 74 68 6d 65 74 69 63  20 70 72 6f 67 72 65 73  |ithmetic progres|
000001c0  73 69 6f 6e 2c 20 65 67  20 31 20 33 20 35 20 37  |sion, eg 1 3 5 7|
000001d0  0a 39 20 65 74 63 2e 0a  61 3d 73 74 61 72 74 69  |.9 etc..a=starti|
000001e0  6e 67 20 6e 75 6d 62 65  72 20 28 65 67 20 31 29  |ng number (eg 1)|
000001f0  0a 64 3d 63 6f 6d 6d 6f  6e 20 64 69 66 66 65 72  |.d=common differ|
00000200  65 6e 63 65 20 28 65 67  20 32 29 0a 0a 53 3c 6e  |ence (eg 2)..S<n|
00000210  3e 3d 28 6e 2f 32 29 28  32 61 2b 28 6e 2d 31 29  |>=(n/2)(2a+(n-1)|
00000220  64 29 0a 46 6f 72 20 61  6e 20 61 72 69 74 68 6d  |d).For an arithm|
00000230  65 74 69 63 20 70 72 6f  67 72 65 73 73 69 6f 6e  |etic progression|
00000240  2c 20 65 67 20 31 20 33  20 35 20 37 0a 39 20 65  |, eg 1 3 5 7.9 e|
00000250  74 63 2e 0a 53 3c 6e 3e  3d 73 75 6d 20 6f 66 20  |tc..S<n>=sum of |
00000260  74 68 65 20 6e 75 6d 62  65 72 73 20 75 70 20 74  |the numbers up t|
00000270  6f 20 74 65 72 6d 20 6e  2e 0a 61 3d 73 74 61 72  |o term n..a=star|
00000280  74 69 6e 67 20 6e 75 6d  62 65 72 20 28 65 67 20  |ting number (eg |
00000290  31 29 0a 64 3d 63 6f 6d  6d 6f 6e 20 64 69 66 66  |1).d=common diff|
000002a0  65 72 65 6e 63 65 20 28  65 67 20 32 29 0a 6e 74  |erence (eg 2).nt|
000002b0  68 20 74 65 72 6d 3d 61  72 5e 28 6e 2d 31 29 0a  |h term=ar^(n-1).|
000002c0  46 6f 72 20 61 20 67 65  6f 6d 65 74 72 69 63 20  |For a geometric |
000002d0  70 72 6f 67 72 65 73 73  69 6f 6e 2c 20 65 67 20  |progression, eg |
000002e0  31 20 32 20 34 20 38 20  31 36 0a 61 3d 73 74 61  |1 2 4 8 16.a=sta|
000002f0  72 74 69 6e 67 20 6e 75  6d 62 65 72 20 28 65 67  |rting number (eg|
00000300  20 31 29 0a 72 3d 63 6f  6d 6d 6f 6e 20 72 61 74  | 1).r=common rat|
00000310  69 6f 20 28 65 67 20 32  29 0a 0a 0a 53 3c 6e 3e  |io (eg 2)...S<n>|
00000320  3d 61 28 31 2d 72 5e 6e  29 2f 28 31 2d 72 29 0a  |=a(1-r^n)/(1-r).|
00000330  46 6f 72 20 61 20 67 65  6f 6d 65 74 72 69 63 20  |For a geometric |
00000340  70 72 6f 67 72 65 73 73  69 6f 6e 2c 20 65 67 20  |progression, eg |
00000350  31 20 32 20 34 20 38 20  31 36 0a 53 3c 6e 3e 3d  |1 2 4 8 16.S<n>=|
00000360  73 75 6d 20 6f 66 20 74  68 65 20 6e 75 6d 62 65  |sum of the numbe|
00000370  72 73 20 75 70 20 74 6f  20 74 65 72 6d 20 6e 2e  |rs up to term n.|
00000380  0a 61 3d 73 74 61 72 74  69 6e 67 20 6e 75 6d 62  |.a=starting numb|
00000390  65 72 20 28 65 67 20 31  29 0a 72 3d 63 6f 6d 6d  |er (eg 1).r=comm|
000003a0  6f 6e 20 72 61 74 69 6f  20 28 65 67 20 32 29 0a  |on ratio (eg 2).|
000003b0  0a 53 3c 69 3e 3d 61 2f  28 31 2d 72 29 0a 46 6f  |.S<i>=a/(1-r).Fo|
000003c0  72 20 61 20 67 65 6f 6d  65 74 72 69 63 20 70 72  |r a geometric pr|
000003d0  6f 67 72 65 73 73 69 6f  6e 2c 20 77 68 65 6e 20  |ogression, when |
000003e0  7c 72 7c 3c 31 2c 0a 65  67 20 31 20 31 2f 32 20  ||r|<1,.eg 1 1/2 |
000003f0  31 2f 34 20 31 2f 38 20  31 2f 31 36 0a 53 3c 69  |1/4 1/8 1/16.S<i|
00000400  3e 3d 73 75 6d 20 6f 66  20 74 65 72 6d 73 20 74  |>=sum of terms t|
00000410  6f 20 69 6e 66 69 6e 69  74 79 0a 61 3d 73 74 61  |o infinity.a=sta|
00000420  72 74 69 6e 67 20 6e 75  6d 62 65 72 20 28 65 67  |rting number (eg|
00000430  20 31 29 0a 72 3d 63 6f  6d 6d 6f 6e 20 72 61 74  | 1).r=common rat|
00000440  69 6f 20 28 65 67 20 bd  29 0a 65 3d 28 31 2f 30  |io (eg .).e=(1/0|
00000450  21 29 2b 28 31 2f 31 21  29 2b 28 31 2f 32 21 29  |!)+(1/1!)+(1/2!)|
00000460  2b 28 31 2f 33 21 29 2b  28 31 2f 34 21 29 2e 2e  |+(1/3!)+(1/4!)..|
00000470  2e 0a 54 68 69 73 20 69  73 20 6f 6e 65 20 77 61  |..This is one wa|
00000480  79 20 6f 66 20 63 61 6c  63 75 6c 61 74 69 6e 67  |y of calculating|
00000490  20 65 20 28 32 2e 37 31  38 29 2c 0a 77 68 65 72  | e (2.718),.wher|
000004a0  65 20 61 21 20 69 73 20  74 68 65 20 66 61 63 74  |e a! is the fact|
000004b0  6f 72 69 61 6c 20 6f 66  20 61 3a 0a 61 28 61 2d  |orial of a:.a(a-|
000004c0  31 29 28 61 2d 32 29 28  61 2d 33 29 2e 2e 20 75  |1)(a-2)(a-3).. u|
000004d0  6e 74 69 6c 20 61 2d 6e  3d 31 0a 4e 6f 74 65 3a  |ntil a-n=1.Note:|
000004e0  20 30 21 3d 31 0a 0a 28  31 2b 78 29 5e 6e 3d 31  | 0!=1..(1+x)^n=1|
000004f0  2b 5b 6e 78 5d 2b 5b 6e  28 6e 2d 31 29 78 b2 2f  |+[nx]+[n(n-1)x./|
00000500  32 21 5d 2b 2e 2e 2e 0a  4b 6e 6f 77 6e 20 61 73  |2!]+....Known as|
00000510  20 74 68 65 20 70 6f 77  65 72 20 73 65 72 69 65  | the power serie|
00000520  73 2c 20 66 6f 72 20 65  78 70 61 6e 73 69 6f 6e  |s, for expansion|
00000530  0a 6f 66 20 74 68 65 20  62 72 61 63 6b 65 74 20  |.of the bracket |
00000540  28 31 2b 78 29 5e 6e 20  77 68 65 72 65 20 6e 20  |(1+x)^n where n |
00000550  69 73 20 61 6e 79 20 72  65 61 6c 0a 6e 75 6d 62  |is any real.numb|
00000560  65 72 20 28 70 6f 73 69  74 69 76 65 2c 20 6e 65  |er (positive, ne|
00000570  67 61 74 69 76 65 2c 20  69 6e 74 65 67 65 72 20  |gative, integer |
00000580  61 6e 64 0a 6e 6f 6e 2d  69 6e 74 65 67 65 72 29  |and.non-integer)|
00000590  2e 0a 0a 0a 0a 0a 0a 0a  0a 0a 0a 0a 0a 0a 0a 0a  |................|
000005a0  0a 0a 0a 0a 0a 0a 0a 0a  0a 0a 0a 0a 0a 0a 0a 0a  |................|
*
000005f0  0a 0a 0a 0a 0a 0a 0a 0a  0a 0a 0a 0a 0a 0a 0a     |...............|
000005ff