This takes me back in time, to c. 1982 when I got curious about how computers calculated trig functions. Luckily I was using one of the first OSS systems (modulo AT&T lawyers): Unix V7. So I pulled up the source and took a look. You can still see it here: https://github.com/v7unix/v7unix/blob/master/v7/usr/src/libm... There's a comment referencing "Hart & Cheney", which is this book : https://www.google.com/books/edition/Computer_Approximations... Also luckily I had access to a library that had the book which I was able to read, at least in part. This taught me a few things : that the behavior of a computer can be a white box, not a black box; the value of having access to the source code; to use comments effectively; that for many difficult tasks someone probably had written a book on the subject. Also that polynomials can approximate transcendental functions.