Trig functions

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Kokopeelle - 30 Sep 2006 04:41 GMT

I have been studing the early formation fo trig tables by Ptolemy abotu
100-200Ad. I now would like to know the methodolgy tht ecel uses for
calculating these functions. I'm not interested in the detailed code, just
the general methods.

Can anyone help?

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rk koko pele

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paul - 30 Sep 2006 07:58 GMT

the excel functions for trig are
COS
ACOS
ACOSH
COSH
SIN
ASIN
SINH
ASINH
TAN
ATAN
TANH
ATANH
RADIANS
DEGREES
excel works in radians by default so the radians and degree function are
there to swap back and forth

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paul
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> I have been studing the early formation fo trig tables by Ptolemy abotu
> 100-200Ad. I now would like to know the methodolgy tht ecel uses for
> calculating these functions. I'm not interested in the detailed code, just
> the general methods.
>
> Can anyone help?

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Bernard Liengme - 30 Sep 2006 19:11 GMT

My bet is that Excel uses a series expansion
sin(x) = x -x^3/3! + x^5/5! - x^7/7! ...

Google on binomial, Taylor and Maclaurin series to learn more (or read a
math textbook)
best wishes

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Bernard V Liengme
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>I have been studing the early formation fo trig tables by Ptolemy abotu
> 100-200Ad. I now would like to know the methodolgy tht ecel uses for
[quoted text clipped - 3 lines]
>
> Can anyone help?

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Dana DeLouis - 30 Sep 2006 20:58 GMT

My guess would be some version of the "CORDIC algorithm."
One of many search hits:
http://www.dspguru.com/info/faqs/cordic2.htm (See 2.1)

http://www.andraka.com/cordic.htm
etc..

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Dana DeLouis
Windows XP & Office 2003

> My bet is that Excel uses a series expansion
> sin(x) = x -x^3/3! + x^5/5! - x^7/7! ...
[quoted text clipped - 10 lines]
>>
>> Can anyone help?

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