Check out https://www.chebfun.org/ https://www.chebfun.org/ if you want to see some crazy stuff you can do with polynomials! Also the book Approximation Theory

Check out https://www.chebfun.org/ https://www.chebfun.org/ if you want to see some crazy stuff you can do with polynomials! Also the book Approximation Theory and Approximation Practice https://epubs.siam.org/doi/book/10.1137/1.9781611975949 https://epubs.siam.org/doi/book/10.1137/1.9781611975949 is really great, by the author of Chebfun.