\documentclass{article}
\title{Question 4}
\author{Rakshit Rabugotra}
\date{}

\begin{document}

\section{List of Mathematical functions}
\begin{itemize}
    \item Trigonometric functions
    \begin{itemize}
        \item[-]sine
        \item[-]cosine
        \item[-]tangent
    \end{itemize}
    \item Special functions
    \begin{itemize}
        \item[-]Beta function
        \item[-]Gamma function
        \item[-]Riemann zeta function
    \end{itemize}
\end{itemize}

\end{document}