Re: standard trig functions for degrees ?

On 4/27/26 2:15 PM, Stavros Macrakis wrote:

> I don't know what exactly Henry wants. If it's just numeric 
> computation, that's trivial. As he says, it's < 1k of code, which he 
> can write himself.
>
> The hard part is symbolic computation.
>
> I'd think that someone working in degrees would like to see things like:
>
>     *sind(x/2),halfangles => sqrt(1-cosd(x))/sqrt(2) *(for 0<x<360)
>
>
> This gets messier. Yes, you can write pattern matching rules that 
> change all instances of *cos(...)* to *cosd(...)*, etc.
>
> But what about, say, *limit(sind(x)/x,x,0)*? That gives *%pi/180*; is 
> that what is expected, or does the user want to see *(%pi/180)°***or 
> maybe*1*? I've never worked in degrees beyond elementary trig, so I 
> don't know what the user expects, and whether the system (as opposed 
> to the user) needs to keep track of degrees vs. radians.
>
> Or am I overthinking it?

I think this is the main problem. I have no interest in making the 
degree functions support all the symbolic manipulations that we have.

Like you, I only used degrees for trig computations as done in a high 
school trig class. Anything more means working in radians.

So if that’s what desired, that’s fine with me. Maybe someone will write 
a simple package to compute the trig functions (and inverses) using 
degrees. That could fit in the share or contrib directories. Or on 
someone’s git repo somewhere.

&#8203;

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