Update chebyshev.jl

Author: putianyi889

src/classical/chebyshev.jl

@@ -159,7 +159,7 @@ weightedgrammatrix(::ChebyshevU{V}) where V = Diagonal(Fill(convert(V,π)/2,∞)
 @simplify *(A::QuasiAdjoint{<:Any,<:Weighted{<:Any,<:ChebyshevU}}, B::ChebyshevU) = weightedgrammatrix(ChebyshevU{promote_type(eltype(A),eltype(B))}())
 
 function grammatrix(A::ChebyshevT{T}) where T
-    f = (k,j) -> isodd(j-k) ? zero(T) : -((T(2)*(-1 + j^2 + k^2))/((-1 + j - k)*(-1 + j + k)*(1 + j - k)*(1 + j + k))
+    f = (k,j) -> isodd(j-k) ? zero(T) : -(T(2)*(-1 + j^2 + k^2))/((-1 + j - k)*(-1 + j + k)*(1 + j - k)*(1 + j + k))
     BroadcastMatrix{T}(f, 0:∞, (0:∞)')
 end