Re: Angle Units For Trig Functions

On Wed, 23 Oct 2024 21:21:41 +0000, Neil wrote:

Steven G. Kargl <sgk@removetroutmask.apl.washington.edu> wrote:

On Wed, 23 Oct 2024 06:25:02 +0000, Lawrence D'Oliveiro wrote:
 

On Wed, 23 Oct 2024 07:59:24 +0200, R Daneel Olivaw wrote:
 

Lawrence D'Oliveiro wrote:
>

On Wed, 23 Oct 2024 04:06:26 -0000 (UTC), David Jones wrote:
 

Did you take a high school trigonometry class?

 
You seem obsessed with that.

 
So your favourite functions return an exact result for sin 30°. Do
they return an exact result for cos 30° as well?
 
 

Nope.  For REAL x, COSD(x) returns an exact result for all N >= 0 that
satisfies 60+N*360 < 2**23.
 
 

Could you give an example of where sind and cosd might be of use in a
piece of numerical software?

I don't use degree trig functions in my codes. Conversion of lat/long
to UTM may be a place one might use sind and/or cosd.  Seattle is
at 47.6061° N, 122.3328° W.  I've never seen someone refer to the
location as 0.83088 N, 2.13511 W.

--
steve