\documentclass[12pt]{book}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{amsthm}
\usepackage[pdftex]{graphicx}
\usepackage{asymptote}
\usepackage{gensymb}
\newtheorem{theorem}{Theorem}
\newtheorem{lemma}[theorem]{Lemma}
\newtheorem{corollary}[theorem]{Corollary}
\newtheorem{definition}{Definition}
\newtheorem{remark}{Remark}
\newtheorem{question}{Question}
\newtheorem{exercise}{Exercise}
\newtheorem{claim}{Claim}
\newcommand{\area}{\textrm{Area}}
\newcommand{\vect}[1]{\overline{#1}}
\newcommand{\pd}[2]{\frac{\partial #1}{\partial #2}}
\begin{document}
\input{./Ceva/chapter1.tex}
\input{./CenterOfMass/chapter2.tex}
\input{./chapter3/chapter3.tex}
\input{./chapter4/chapter4.tex}
\input{./chapter5/chapter5.tex}
\input{./chapter6/chapter6.tex}
\end{document}