~edwargix/tallyard

ddcac21be1e2dd829da09201e417551fa969fb0e — David Florness 5 years ago cac0b07
OreSec talk: fix sum expansions
1 files changed, 10 insertions(+), 10 deletions(-)

M doc/oresec-talk/tallyard.tex
M doc/oresec-talk/tallyard.tex => doc/oresec-talk/tallyard.tex +10 -10
@@ 235,10 235,10 @@
  \begin{itemize}
  \item Everyone now has $S_1$, $S_2$, $\dots$, $S_k$: \pause
    \begin{align*}
      S_1 &= \sum_{j=1}^k c_j + x_1 \sum_{j=1}^k a_{(j,1)} + x_1^2 \sum_{j=1}^k a_{(j,2)} + \cdots + x_1^{k-1} \sum_{j=1}^k a_{(j,2)} \\
      S_1 &= \sum_{j=1}^k c_j + x_2 \sum_{j=1}^k a_{(j,1)} + x_2^2 \sum_{j=1}^k a_{(j,2)} + \cdots + x_2^{k-1} \sum_{j=1}^k a_{(j,2)} \\
      S_1 &= \sum_{j=1}^k c_j + x_1 \sum_{j=1}^k a_{(j,1)} + x_1^2 \sum_{j=1}^k a_{(j,2)} + \cdots + x_1^{k-1} \sum_{j=1}^k a_{(j,k-1)} \\
      S_1 &= \sum_{j=1}^k c_j + x_2 \sum_{j=1}^k a_{(j,1)} + x_2^2 \sum_{j=1}^k a_{(j,2)} + \cdots + x_2^{k-1} \sum_{j=1}^k a_{(j,k-1)} \\
          &\vdots \\
      S_k &= \sum_{j=1}^k c_j + x_k \sum_{j=1}^k a_{(j,1)} + x_k^2 \sum_{j=1}^k a_{(j,2)} + \cdots + x_k^{k-1} \sum_{j=1}^k a_{(j,2)}
      S_k &= \sum_{j=1}^k c_j + x_k \sum_{j=1}^k a_{(j,1)} + x_k^2 \sum_{j=1}^k a_{(j,2)} + \cdots + x_k^{k-1} \sum_{j=1}^k a_{(j,k-1)}
    \end{align*} \pause
  \item These are $k$ points all on the same $k-1$ degree polynomial:
    \begin{equation*}


@@ 253,17 253,17 @@
    coefficients and constant term of it with a little linear algebra: \pause
    \begin{equation*}
      \begin{bmatrix}
        1 & x_1 & x_1^2 & \cdots & x_1^k \\
        1 & x_2 & x_2^2 & \cdots & x_2^k \\
        1 & x_1 & x_1^2 & \cdots & x_1^{k-1} \\
        1 & x_2 & x_2^2 & \cdots & x_2^{k-1} \\
        \vdots & & & \ddots \\
        1 & x_k & x_k^2 & \cdots & x_k^k
        1 & x_k & x_k^2 & \cdots & x_k^{k-1}
      \end{bmatrix}
            \begin{bmatrix}
              \sum_{j=1}^k c_j \\
              \sum_{j=1}^k a_{(j,1)} \\
              \sum_{j=1}^k a_{(j,2)} \\
              \vdots \\
              \sum_{j=1}^k a_{(j,2)}
              \sum_{j=1}^k a_{(j,k-1)}
            \end{bmatrix} =
            \begin{bmatrix}
              S_1 \\


@@ 279,10 279,10 @@
  \begin{equation*}
    \text{RREF}\left(
      \begin{bmatrix}
        1 & x_1 & x_1^2 & \cdots & x_1^k & S_1 \\
        1 & x_2 & x_2^2 & \cdots & x_2^k & S_2 \\
        1 & x_1 & x_1^2 & \cdots & x_1^{k-1} & S_1 \\
        1 & x_2 & x_2^2 & \cdots & x_2^{k-1} & S_2 \\
        \vdots & & & \ddots \\
        1 & x_k & x_k^2 & \cdots & x_k^k & S_k
        1 & x_k & x_k^2 & \cdots & x_k^{k-1} & S_k
      \end{bmatrix}
    \right)
  \end{equation*}