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sin (u+v)

sin u cos v + cos u sin v

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sin (u-v)

sin u cos v - cos u sin v

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cos (u+v)

cos u cos v - sin u sin v

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cos (u-v)

cos u cos v + sin u sin v

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tan (u+v)

tan u + tan v

-----------------------

1 - tan u tan v

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tan (u-v)

tan u - tan v

-----------------

1 + tan u tan v

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cos 2u

1- 2sin^2 u

2cos^2 u -1

cos^2 u - sin^2 u

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tan 2u

2tan u

-----------------

1- tan^2 u

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sin^2 u

1-cos 2u

-------------

2

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cos^2 u

1 + cos 2u

----------------

2

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tan^2 u

1 - cos 2u

----------------

1+ cos 2u

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sin u/2

± √ ( 1 - cos u) / 2

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cos u/2

± √ (1 + cos u) /2

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tan u/2

sin u

---------

1 + cos u

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sum of a geometric series

Sn = a1 ( [1-r^(n-1) / 1-r ] )

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sum of infinite geometric series

a1

----

1-r if -1<r<1

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sum of an arithmetic series

Sn = n/2 ( 2a1 + (n-1) d )

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nth term of a geometric sequence

a n = a1 ( r^(n-1) )

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nth term of an arithmetic sequence

a1 + ( n - 1) d

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