test

1変数多項式の場合
\begin{align}
m_i&=\text{INDEX( LINEST($y$のデータ列,$\color{red}{\text{$\,x$のデータ列^{$1,2,\cdots,N$}}}$),$\, 1$,$\, N-i+1$)}\\
f(x)&=\text{TREND$\bigl(\,y$のデータ列,$\color{red}{\text{$\,x$のデータ列^{$1,2,\cdots,N$}}}$,$\color{red}{\text{$\,x$^{$1,2,\cdots,N$}}}\,\bigr)$}
\end{align}

https://text.baldanders.info/release/2019/09/mathjax-v3-is-released/