Friends,
I know that Chebyshev polynomials of degree n can put in the following form: Tn(x)=Cos[n*arccos[ x] ], x pertaining to [-1,1]. When I create the command
Plot[{ChebyshevT[2, x], ChebyshevT[3, x], ChebyshevT[4, x]}, {x, -2, 2}, PlotLegend -> {"T2", "T3", "T4"}, LegendPosition -> {1, 0}]
It works well and I think it must not work well because "ArcCos for x>1" makes no sense. Anybody could help me?
Thank you,
Ana
