Implement trigonometric functions

[folivetti]

Example

x2 = do a <- newFromInterval (-1 ... -0.1)
             return.interval $ cos a
evalAFM x2

[Soupstraw]

Some of the functions have not yet been implemented fully, only in some specific cases.
The issue with cosine is that it can be both concave and convex in the region, so it's not trivial to use min-range approximation in those cases.
I won't be able to work on it for about a month, but it will need to be implemented at some point.

[folivetti]

maybe you can check this library to see how they dealt with it

https://github.com/ogay/libaffa