What motivated the development of the Unit Circle? By this I don't mean necessarily the stars, but rather the functions. I personally find it impressive that sines, and cosines for instance, have this property to be a function that returns the respective heights and lengths of a triangle.

And while we're at that, logarithms fascinate me for the same reason. What kind of Autism led us to develop logarithms, trig functions, and other such things. It is genuinely really cool. If you can link me some articles or direct me to some books, I would also like that as well...

And while we're at that, what other autism is similar to this-- have we ever made functions of this kind before?

Also, what are inverse trig functions? Do we have a series expansion? Also can someone explain CORDIC to me? I know I am asking too much, but this area of computational history fascinates me and is very little talked about, even though it is the most interesting topic. We use logs and trig functions daily, but we never really stop and question how and why... Just stuff like this is cool and all.