答案1
请选择:
\documentclass{article}
\usepackage{amsmath}
\newcommand{\subquoteA}{%
\scriptscriptstyle
\prime\mspace{-1mu}\prime
}
\newcommand{\subquoteB}{\textup{\raisebox{-0.5ex}{''}}}
\begin{document}
\[
v_{\prime\prime}^2 = 1330w_{\prime\prime}^2 + 1381
\]
\[
v_{\subquoteA}^2 = 1330w_{\subquoteA}^2 + 1381
\]
\[
v_{\subquoteB}^2 = 1330w_{\subquoteB}^2 + 1381
\]
\end{document}