Errors when trying to insert graphics file

Question

I want to include a graphics called quadratic.pdf in my LaTeX document, which only contains the image show below.

While compiling, I get the following errors:

Line 1: Fatal Error No output file produced 

Line 5: !LaTeX error. File: 'quadratic.pdf.sty' not found. 

Where am I going wrong?

\documentclass[oneside]{book}

\usepackage{graphicx}
\usepackage{quadratic.pdf}

\begin{document}

\chapter*{Basic Graphics}

\begin{figure}[h]
\centering
\includegraphics[width=0.5\linewidth]{quadratic}
\caption{The graphics file named \texttt{quadratic}.}
\end{figure}

\end{document}

Answer 1

Too long as a comment.

\documentclass[oneside]{book}

\usepackage{graphicx}
%\graphicspath{{./}{./SubdirOne/}{./SubdirTwo/}<... more items here ...>{./SubdirOne/SubsubdirOne/}}
\graphicspath{{./}{./SubdirOne/}{./SubdirTwo/}}

\begin{document}

\chapter*{Basic Graphics}

\begin{figure}[h]
\centering
\includegraphics[width=0.5\linewidth]{quadratic}
\caption{The graphics file named \texttt{quadratic}.}
\end{figure}

\end{document}