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[WP-34S] DEG and RAD - diffs
06-07-2014, 03:38 AM
Post: #32
RE: [WP-34S] DEG and RAD - diffs
(06-07-2014 01:46 AM)Claudio L. Wrote:  You're right, that term won't lose precision.

As Pauli already pointed out there's no cancellation since:

\[\frac{1}{\sqrt{1+x^2}}=1-\frac{x^2}{2}+\ldots\]

For a small x this will be close to 1 and thus \(\sin(x)\approx\tan(x)\).

Quote:I looked at my code, and here's where I was losing digits:

// COMPUTE ACOS(X) = ATAN2(SQRT(1-X^2),X)

when x~1 (ACOS(X)~0) I couldn't get all the digits right

You might have a look at how the HP-48 calculates the complex arccos.

Cheers
Thomas
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Messages In This Thread
[WP-34S] DEG and RAD - diffs - pito - 06-05-2014, 12:08 AM
RE: DEG and RAD - diffs - Paul Dale - 06-05-2014, 12:53 AM
RE: DEG and RAD - diffs - pito - 06-05-2014, 06:27 AM
RE: [WP-34S] DEG and RAD - diffs - pito - 06-05-2014, 01:38 PM
RE: [WP-34S] DEG and RAD - diffs - Dieter - 06-05-2014, 11:12 AM
RE: [WP-34S] DEG and RAD - diffs - pito - 06-05-2014, 06:04 PM
RE: [WP-34S] DEG and RAD - diffs - pito - 06-05-2014, 07:57 PM
RE: [WP-34S] DEG and RAD - diffs - pito - 06-05-2014, 10:07 PM
RE: [WP-34S] DEG and RAD - diffs - Dieter - 06-06-2014, 05:27 PM
RE: [WP-34S] DEG and RAD - diffs - Thomas Klemm - 06-07-2014 03:38 AM
RE: [WP-34S] DEG and RAD - diffs - pito - 06-07-2014, 12:57 PM



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