Talk:Cosine of Integer Multiple of Argument/Formulation 1

What's going on with the line after pascal's rule? I didn't know binomial coefficients could be converted into fractions --Ybab321 (talk) 12:05, 2 July 2020 (UTC)

The parentheses for binomial coefficients should have a tiny subscript b at the bottom right to clarify that they are binomial coefficients instead of regular parentheses.

don't think so --prime mover (talk) 14:38, 2 July 2020 (UTC)

In that line after Pascal's rule, one of the parentheses is a regular parentheses and the other one is a binomial coefficient parentheses.

\(\ds \binom {n +1 - k } {k }\)

\(=\)

\(\ds \frac {n + 1 - k } k \times \binom {n - k } {k - 1 }\)

\(\ds \)

\(=\)

\(\ds \frac {n + 1 - k } k \times \frac {\paren {n - k }! } {\paren {k - 1 }! \paren {n - 2 k + 1 }! }\)

Does this clarify the issue? --Robkahn131 (talk) 14:00, 2 July 2020 (UTC)

That extra step needs to be included in the derivation. As it stands the jump is too big. --prime mover (talk) 14:38, 2 July 2020 (UTC)

I've added that extra step along with a link to the rule being used that justfies it. --prime mover (talk) 15:39, 2 July 2020 (UTC)

Thanks! --Robkahn131 (talk) 18:49, 2 July 2020 (UTC)

Thanks here too, reads perfectly now :) --Ybab321 (talk) 13:40, 3 July 2020 (UTC)