ChebyshevT[\[Nu], z] == ((1/2) (Cos[(Pi \[Nu])/2] (Sqrt[-z] + z^\[Nu] (-z)^(1/2 + \[Nu]) (1 + (Sqrt[z^2] Sqrt[-1 + z^2])/z^2)^(2 \[Nu])) + Sin[(Pi \[Nu])/2] (-Sqrt[z] + (-z)^\[Nu] z^(1/2 + \[Nu]) (1 + (Sqrt[z^2] Sqrt[-1 + z^2])/z^2)^(2 \[Nu]))))/ ((-z)^((\[Nu] + 1)/2) z^(\[Nu]/2) (1 + (Sqrt[z^2] Sqrt[-1 + z^2])/z^2)^ \[Nu]) /; !IntervalMemberQ[Interval[{-1, 0}], z]

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2007-05-02