User talk:76.190.135.206

trigonometric polynomials
You can see from the cited Rudin book that the coefficients of a (complex) trigonometric polynomial are in general complex, but set up so that when coefficients are real, the polynomial is real (as a function of the interval [0, 2π) or (-π, π]). jacobolus (t) 00:34, 31 October 2022 (UTC)