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Having read sin of pi radians, it seems as though sin is iffy around truncated inputs.

That said, I'm not quite grokking why it's this bad.

Given this org-mode table:

|  i |  $x_i$ |    $sin(x^3)$ |        $x^3$ |
|----+--------+---------------+--------------|
|  0 | -0.785 | -8.4426965e-3 |  -0.48373663 |
|  1 | -0.549 | -2.8879774e-3 |  -0.16546915 |
|  2 | -0.313 | -5.3519292e-4 | -0.030664297 |
|  3 | -0.077 | -7.9680040e-6 |  -4.56533e-4 |
|  4 |  0.159 |  7.0156633e-5 |  4.019679e-3 |
|  5 |  0.395 |  1.0756440e-3 |  0.061629875 |
|  6 |  0.631 |  4.3849440e-3 |   0.25123959 |
|  7 |  0.867 |   0.011374316 |   0.65171436 |
|  8 |  1.103 |   0.023418776 |    1.3419197 |
|  9 |  1.339 |   0.041888230 |    2.4007212 |
| 10 |  1.575 |   0.068136908 |    3.9069844 |
#+TBLFM: $2=(-3.14/4)+(0.236*$1)::$3=sin($2^3)::$4=$2^3 

The column with sin(x^3) is very far off. I can tell that the x^3 column is roughly what I expect.

To take an example, sin(1.575^3) should be -0.69282 according to my calculator, not 0.06813 as shown by this table.

What am I getting wrong here?

Justin Abrahms
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1 Answers1

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As documented, the argument of sin is in degrees, not radians. See e.g. Angular Modes.

Use

$3=sin($4);R

to use radians intead.

choroba
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