History of Chebyshev polynomials of the first kind $T_n$

   comment-orthogonal: The $T_n$ are orthogonal with respect to the inner product $\langle     f,g\rangle = \int_{-1}^1 f(x)g(x)(1-x^2)^{-1/2} dx$.+  comment-dickson: '$2\,T_n(x) = D_n(2x, 1)$, where $D_n$ are the Dickson polynomials+    HREF{Dickson_polynomials_of_the_first_kind}: the same recurrence, written so that+    it makes sense over a finite field, where these permute the field.' Formulas:   formula-recurrence: $T_0(x) = 1$,  $T_1(x) = x$,  and $T_{n+1}(x) = 2x T_n(x)-T_{n-1}(x)$