Home » Archimedes archive » Archimedes World » AW-1996-07.adf » !Ignotum_Ignotum » !Ignotum/Formulae/Trig

!Ignotum/Formulae/Trig

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 » Archimedes World » AW-1996-07.adf » !Ignotum_Ignotum
Filename: !Ignotum/Formulae/Trig
Read OK:
File size: 04B9 bytes
Load address: 0000
Exec address: 0000
File contents
# Maths > Trig. Identities
cotx=1/tanx
Cotx is a function of x equal to the
reciprocal of tanx.



cosecx=1/sinx
Cosecx is a function of x equal to the
reciprocal of sinx.



secx=1/cosx
Secx is a function of x equal to the
reciprocal of cosx.



sin�x+cos�x=1
A commonly used identity, used to obtain
many of the more complex identities.
Note: sin�x=(sinx)�


cot�x+1=cosec�x





tan�x+1=sec�x





cos�x=�(1+cos2x)





sin�x=�(1-cos2x)





sin2x=2sinxcosx





cos2x=1-2sin�x





cos2x=2cos�x-1





cos2x=cos�x-sin�x





tan2x=(2tanx)/(1-tan�x)





sin(A+B)=sinAcosB+cosAsinB
Where A and B are both angles.




sin(A-B)=sinAcosB-cosAsinB
Where A and B are both angles.




cos(A+B)=cosAcosB-sinAsinB
Where A and B are both angles.




cos(A-B)=cosAcosB+sinAsinB
Where A and B are both angles.




tan(A+B)=(tanA+tanB)/(1-tanAtanB)
Where A and B are both angles.




tan(A-B)=(tanA-tanB)/(1+tanAtanB)
Where A and B are both angles.




2sinAcosB=sin(A+B)+sin(A-B)
Where A and B are both angles.




2cosAsinB=sin(A+B)-sin(A-B)
Where A and B are both angles.




2cosAcosB=cos(A+B)+cos(A-B)
Where A and B are both angles.




-2sinAsinB=cos(A-B)-cos(A-B)
Where A and B are both angles.
















00000000  23 20 4d 61 74 68 73 20  3e 20 54 72 69 67 2e 20  |# Maths > Trig. |
00000010  49 64 65 6e 74 69 74 69  65 73 0a 63 6f 74 78 3d  |Identities.cotx=|
00000020  31 2f 74 61 6e 78 0a 43  6f 74 78 20 69 73 20 61  |1/tanx.Cotx is a|
00000030  20 66 75 6e 63 74 69 6f  6e 20 6f 66 20 78 20 65  | function of x e|
00000040  71 75 61 6c 20 74 6f 20  74 68 65 0a 72 65 63 69  |qual to the.reci|
00000050  70 72 6f 63 61 6c 20 6f  66 20 74 61 6e 78 2e 0a  |procal of tanx..|
00000060  0a 0a 0a 63 6f 73 65 63  78 3d 31 2f 73 69 6e 78  |...cosecx=1/sinx|
00000070  0a 43 6f 73 65 63 78 20  69 73 20 61 20 66 75 6e  |.Cosecx is a fun|
00000080  63 74 69 6f 6e 20 6f 66  20 78 20 65 71 75 61 6c  |ction of x equal|
00000090  20 74 6f 20 74 68 65 0a  72 65 63 69 70 72 6f 63  | to the.reciproc|
000000a0  61 6c 20 6f 66 20 73 69  6e 78 2e 0a 0a 0a 0a 73  |al of sinx.....s|
000000b0  65 63 78 3d 31 2f 63 6f  73 78 0a 53 65 63 78 20  |ecx=1/cosx.Secx |
000000c0  69 73 20 61 20 66 75 6e  63 74 69 6f 6e 20 6f 66  |is a function of|
000000d0  20 78 20 65 71 75 61 6c  20 74 6f 20 74 68 65 0a  | x equal to the.|
000000e0  72 65 63 69 70 72 6f 63  61 6c 20 6f 66 20 63 6f  |reciprocal of co|
000000f0  73 78 2e 0a 0a 0a 0a 73  69 6e b2 78 2b 63 6f 73  |sx.....sin.x+cos|
00000100  b2 78 3d 31 0a 41 20 63  6f 6d 6d 6f 6e 6c 79 20  |.x=1.A commonly |
00000110  75 73 65 64 20 69 64 65  6e 74 69 74 79 2c 20 75  |used identity, u|
00000120  73 65 64 20 74 6f 20 6f  62 74 61 69 6e 0a 6d 61  |sed to obtain.ma|
00000130  6e 79 20 6f 66 20 74 68  65 20 6d 6f 72 65 20 63  |ny of the more c|
00000140  6f 6d 70 6c 65 78 20 69  64 65 6e 74 69 74 69 65  |omplex identitie|
00000150  73 2e 0a 4e 6f 74 65 3a  20 73 69 6e b2 78 3d 28  |s..Note: sin.x=(|
00000160  73 69 6e 78 29 b2 0a 0a  0a 63 6f 74 b2 78 2b 31  |sinx)....cot.x+1|
00000170  3d 63 6f 73 65 63 b2 78  0a 0a 0a 0a 0a 0a 74 61  |=cosec.x......ta|
00000180  6e b2 78 2b 31 3d 73 65  63 b2 78 0a 0a 0a 0a 0a  |n.x+1=sec.x.....|
00000190  0a 63 6f 73 b2 78 3d bd  28 31 2b 63 6f 73 32 78  |.cos.x=.(1+cos2x|
000001a0  29 0a 0a 0a 0a 0a 0a 73  69 6e b2 78 3d bd 28 31  |)......sin.x=.(1|
000001b0  2d 63 6f 73 32 78 29 0a  0a 0a 0a 0a 0a 73 69 6e  |-cos2x)......sin|
000001c0  32 78 3d 32 73 69 6e 78  63 6f 73 78 0a 0a 0a 0a  |2x=2sinxcosx....|
000001d0  0a 0a 63 6f 73 32 78 3d  31 2d 32 73 69 6e b2 78  |..cos2x=1-2sin.x|
000001e0  0a 0a 0a 0a 0a 0a 63 6f  73 32 78 3d 32 63 6f 73  |......cos2x=2cos|
000001f0  b2 78 2d 31 0a 0a 0a 0a  0a 0a 63 6f 73 32 78 3d  |.x-1......cos2x=|
00000200  63 6f 73 b2 78 2d 73 69  6e b2 78 0a 0a 0a 0a 0a  |cos.x-sin.x.....|
00000210  0a 74 61 6e 32 78 3d 28  32 74 61 6e 78 29 2f 28  |.tan2x=(2tanx)/(|
00000220  31 2d 74 61 6e b2 78 29  0a 0a 0a 0a 0a 0a 73 69  |1-tan.x)......si|
00000230  6e 28 41 2b 42 29 3d 73  69 6e 41 63 6f 73 42 2b  |n(A+B)=sinAcosB+|
00000240  63 6f 73 41 73 69 6e 42  0a 57 68 65 72 65 20 41  |cosAsinB.Where A|
00000250  20 61 6e 64 20 42 20 61  72 65 20 62 6f 74 68 20  | and B are both |
00000260  61 6e 67 6c 65 73 2e 0a  0a 0a 0a 0a 73 69 6e 28  |angles......sin(|
00000270  41 2d 42 29 3d 73 69 6e  41 63 6f 73 42 2d 63 6f  |A-B)=sinAcosB-co|
00000280  73 41 73 69 6e 42 0a 57  68 65 72 65 20 41 20 61  |sAsinB.Where A a|
00000290  6e 64 20 42 20 61 72 65  20 62 6f 74 68 20 61 6e  |nd B are both an|
000002a0  67 6c 65 73 2e 0a 0a 0a  0a 0a 63 6f 73 28 41 2b  |gles......cos(A+|
000002b0  42 29 3d 63 6f 73 41 63  6f 73 42 2d 73 69 6e 41  |B)=cosAcosB-sinA|
000002c0  73 69 6e 42 0a 57 68 65  72 65 20 41 20 61 6e 64  |sinB.Where A and|
000002d0  20 42 20 61 72 65 20 62  6f 74 68 20 61 6e 67 6c  | B are both angl|
000002e0  65 73 2e 0a 0a 0a 0a 0a  63 6f 73 28 41 2d 42 29  |es......cos(A-B)|
000002f0  3d 63 6f 73 41 63 6f 73  42 2b 73 69 6e 41 73 69  |=cosAcosB+sinAsi|
00000300  6e 42 0a 57 68 65 72 65  20 41 20 61 6e 64 20 42  |nB.Where A and B|
00000310  20 61 72 65 20 62 6f 74  68 20 61 6e 67 6c 65 73  | are both angles|
00000320  2e 0a 0a 0a 0a 0a 74 61  6e 28 41 2b 42 29 3d 28  |......tan(A+B)=(|
00000330  74 61 6e 41 2b 74 61 6e  42 29 2f 28 31 2d 74 61  |tanA+tanB)/(1-ta|
00000340  6e 41 74 61 6e 42 29 0a  57 68 65 72 65 20 41 20  |nAtanB).Where A |
00000350  61 6e 64 20 42 20 61 72  65 20 62 6f 74 68 20 61  |and B are both a|
00000360  6e 67 6c 65 73 2e 0a 0a  0a 0a 0a 74 61 6e 28 41  |ngles......tan(A|
00000370  2d 42 29 3d 28 74 61 6e  41 2d 74 61 6e 42 29 2f  |-B)=(tanA-tanB)/|
00000380  28 31 2b 74 61 6e 41 74  61 6e 42 29 0a 57 68 65  |(1+tanAtanB).Whe|
00000390  72 65 20 41 20 61 6e 64  20 42 20 61 72 65 20 62  |re A and B are b|
000003a0  6f 74 68 20 61 6e 67 6c  65 73 2e 0a 0a 0a 0a 0a  |oth angles......|
000003b0  32 73 69 6e 41 63 6f 73  42 3d 73 69 6e 28 41 2b  |2sinAcosB=sin(A+|
000003c0  42 29 2b 73 69 6e 28 41  2d 42 29 0a 57 68 65 72  |B)+sin(A-B).Wher|
000003d0  65 20 41 20 61 6e 64 20  42 20 61 72 65 20 62 6f  |e A and B are bo|
000003e0  74 68 20 61 6e 67 6c 65  73 2e 0a 0a 0a 0a 0a 32  |th angles......2|
000003f0  63 6f 73 41 73 69 6e 42  3d 73 69 6e 28 41 2b 42  |cosAsinB=sin(A+B|
00000400  29 2d 73 69 6e 28 41 2d  42 29 0a 57 68 65 72 65  |)-sin(A-B).Where|
00000410  20 41 20 61 6e 64 20 42  20 61 72 65 20 62 6f 74  | A and B are bot|
00000420  68 20 61 6e 67 6c 65 73  2e 0a 0a 0a 0a 0a 32 63  |h angles......2c|
00000430  6f 73 41 63 6f 73 42 3d  63 6f 73 28 41 2b 42 29  |osAcosB=cos(A+B)|
00000440  2b 63 6f 73 28 41 2d 42  29 0a 57 68 65 72 65 20  |+cos(A-B).Where |
00000450  41 20 61 6e 64 20 42 20  61 72 65 20 62 6f 74 68  |A and B are both|
00000460  20 61 6e 67 6c 65 73 2e  0a 0a 0a 0a 0a 2d 32 73  | angles......-2s|
00000470  69 6e 41 73 69 6e 42 3d  63 6f 73 28 41 2d 42 29  |inAsinB=cos(A-B)|
00000480  2d 63 6f 73 28 41 2d 42  29 0a 57 68 65 72 65 20  |-cos(A-B).Where |
00000490  41 20 61 6e 64 20 42 20  61 72 65 20 62 6f 74 68  |A and B are both|
000004a0  20 61 6e 67 6c 65 73 2e  0a 0a 0a 0a 0a 0a 0a 0a  | angles.........|
000004b0  0a 0a 0a 0a 0a 0a 0a 0a  0a                       |.........|
000004b9