no doubt whatever ;)

However 

asin(sin(1:DoubleFloat))::DoubleFloat => 1.0
complexNormalize asin(sin(z)) => z

In* efstruc.spad* (line 423): is?(op, 'asin)  => atan(z / sqrt(1 - z^2))

yields:

(1) -> f(z)== atan(z / sqrt(1 - z^2))
                                                                   Type: 
Void
(2) -> f(sin(z))
   Compiling function f with type Expression(Integer) -> Expression(
      Integer)

                   sin(z)
   (2)  atan(----------------)
               +-------------+
               |        2
              \|- sin(z)  + 1
                                                    Type: 
Expression(Integer)
(3) -> normalize %

   (3)  - z
                       
Apparently we have:

(4) -> test(normalize atan(sin(z)/cos(z)) = normalize 
atan(sin(z)/sqrt(cos(z)^2)))

   (4)  false
                                                                Type: 
Boolean
Either sqrt gives wrong sign or it happens when converting to tan(z/2) ...

(5) -> normalize sqrt(1-sin(z)^2)^-1

             z 2
         tan(-)  + 1
             2
   (5)  -----------
             z 2
         tan(-)  - 1
             2

hm, really strange.


On Thursday, 25 September 2014 02:14:13 UTC+2, Bill Page wrote:
>
> normalize seems to return an anomalous result for asin(sin(r)) 
>
> (1) -> normalize acos(cos(r))-r 
>
>    (1)  0 
>
> (2) -> normalize asin(sin(r))-r 
>
>    (2)  - 2r 
>
> (3) -> normalize acosh(cosh(r))-r 
>
>    (3)  0 
>
> (4) -> normalize asinh(sinh(r))-r 
>
>    (4)  0 
>
> (5) -> normalize atan(tan(r))-r 
>
>    (5)  0 
>
> (6) -> normalize atanh(tanh(r))-r 
>
>    (6)  0 
>

-- 
You received this message because you are subscribed to the Google Groups 
"FriCAS - computer algebra system" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to [email protected].
To post to this group, send email to [email protected].
Visit this group at http://groups.google.com/group/fricas-devel.
For more options, visit https://groups.google.com/d/optout.

Reply via email to