arcsine function asin() gives bad results

[Former user]

Originally reported on Google Code with ID 415

What steps will reproduce the problem?
1.Type "asin(sin(92))"
2.Output is 88?!?!
3.What?!?!

What is the expected output? What do you see instead?
Expected output is 92, instead it is 88.

What version of the product are you using? On what operating system?
0.10.1 on a variant of Debian Linux 7 ("Wheezy.")

Please provide any additional information below.

Perhaps this is similar to the recently fixed bug in the cube root function?

Reported by [e-mail] on 2012-10-20 18:14:58

[Former user]

I retried it instead as 

sin(92)
asin(ans)

and it still gave 88.

Could it be that the asin function is not using enough decimal precision, and/or is
rounding too overzealously at various points in the algorithm?

Reported by [e-mail] on 2012-10-20 18:20:34

[Former user]

by the way it was set to degrees, not radians

Reported by [e-mail] on 2012-10-20 18:22:49

[Former user]

oops, never mind, I know why it is. Feel free to flag this as invalid, I should have
known asin would never yield results higher than 90 degrees, because 92 and 88 have
the same sine. Sorry.

Reported by [e-mail] on 2012-10-20 18:28:32

[Former user]

Reported by helder.pereira.correia on 2012-11-05 05:27:59 - Status changed: Rejected