Thanks for sharing this! I learned how to write floating point math routines from scratch by disassembling the ROMs on my PET and figuring out how they worked.
Nice to see the coefficients for the taylor series computation for sin() in the POLY_SIN table.
No doubt an educational project. However, all the versions of Microsoft 6502 BASIC were collected and annotated by a Michael Steil in 2008.
Docs: https://www.pagetable.com/?p=46
Source: https://github.com/mist64/msbasic