1 The mapping between Cyrillic and Roman scripts is not bijective. As such, some Russian names get transliterated in several forms. One form of the name of Chebyshev is ‘Tchebysheff’, giving rise to the character ‘T’ in the most common notation for Chebyshev polynomials.
2 more precisely, Fourier-Chebyshev series
3 In the initial iteration, locations of extrema of Tn + 1(x) are the obvious starting guesses. In later iterations, old values can be used.