What is this letter called? How to generate it in LaTeX?
\vartheta
\documentclass[margin=3mm]{standalone} \begin{document} $\vartheta_{b}$ \end{document}
\vartheta:\documentclass[margin=3mm]{standalone} \begin{document} $\vartheta_{b}$ \end{document}– Zarko Jun 21 '20 at 18:23