FastTransforms.jl
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Why are second kind Chebyshev points the first kind extrema?
julia> n = 10
10
julia> pts = chebyshevpoints(Float64, n+1, Val(2))
11-element FastTransforms.ChebyshevGrid{2, Float64}:
1.0
0.9510565162951536
0.8090169943749475
0.5877852522924731
0.30901699437494745
0.0
-0.30901699437494745
-0.5877852522924731
-0.8090169943749475
-0.9510565162951536
-1.0
julia> cos.(n.*acos.(pts))
11-element Vector{Float64}:
1.0
-1.0
1.0
-1.0
1.0
-1.0
1.0
-1.0
1.0
-1.0
1.0
Shouldn't they be the roots of the second kind Chebyshev polynomials?