Function Tn(n,x)

Good day.

I could not solve the problem of the Tn (n, x) function. I only changed the function name from Tn to Tc.
But I solved the problem with another method.
Here is the solution that I recommend. It has been checked for many values of n and x [-1: 1] and works correctly.

Function Tc (n, x)

     Dim and As Byte
     Dim R, S, T As Double
     Select Case n
         Case Is = 0
             Tc = 1
         Case Is = 1
             Tc = x
         Case Is> 1
             R = 1
             S = x
         For i = 2 This is n
             T = 2 * x * S - R
             R = S
             S = T
         Next and
         Tc = T
     End Select

End Function

Best Regards