Latex 2.0(Writing With Latex)

\documentclass[fleqn,12pt]{book}
\usepackage{amssymb}
\usepackage{amsfonts}
\usepackage{amsthm}
\usepackage{amstext}
\usepackage{amsxtra}
\usepackage{amsbsy}
\usepackage{curves}
\usepackage[]{shadow}% untuk produce kota berbayang
\usepackage{chaptengah}
\usepackage{graphicx}
\usepackage{color}
%---------------------
\theoremstyle{definition}
\newtheorem{defn}{Definition}[section]
\theoremstyle{plain}
\newtheorem{thm}{Theorem}[section]
\newtheorem{cor}[thm]{Corollary}
\newtheorem{lem}[thm]{Lemma}
\newtheorem{prop}[thm]{Proposition}
%--------------------
%\theoremstyle{Example}
\newtheorem{exl}{Example}[section]
\newtheorem{so}{Solution}[section]
%\newtheorem{la}{\mathfrak{L}\{\}}[section]
\newcommand{\lap}{\mathop{\mathfrak{L}}\limits}
%--------------------
\newcommand{\mut}{\mathop{\mathfrak{U}}\limits}
\newcommand{\lapi}{\mathop{\mathfrak{L}^{-1}}\limits}



\setcounter{chapter}{1}

\begin{document}
\listoffigures
\tableofcontents
\chapter{Differentiation}
\section{Definition}
\begin{defn}
Let $f$ be real-valued function...\\
$$\shabox{$f$ is differentiable at $c$ if" $\lim_{x\to c}\frac{f(x)-f(c)}{x-c}$}$$ 
%----------------------
\subsection{Formula $f^{'}(c)$}
\shabox{$f^{'}(c)=\lim_{x\to c}\frac{f(x)-f(c)}{x-c}$}
%----------------------
\section{How to insert image}
To insert image JPEG or Png are as follows
\begin{itemize}
\item open image
\item Click Print screens
\item open Paint
\item Click Ctrl+V
\item Click crop
\item save
\end{itemize}
%----------------------
\begin{figure}[t!]
\centering
\includegraphics[width=0.5\textwidth]{lat.png}
\caption{Ini gambar saya}
\end{figure}
%---------------------
\section{Insert Graph from Excel}
\begin{figure}[h!]
\centering
\includegraphics[width=0.5\textwidth]{graph1.png}
\caption{Graph $y=x^3+2$}
\end{figure}
%---------------------
\section{How to create matrix}
\begin{verbatim}
\begin{cases}{ccc}
4&7&3\\
5&7&5
\end{cases}

\end{verbatim}
\begin{displaymath}
A=\left(\begin{array}{ccccc}
4&7&3\\
5&7&5\\
1&2&3
\end{array}\right)
\end{displaymath}
%------------
\section{Piecewise function}
\begin{displaymath}
f(x)=\begin{cases}
1,& 0<x<2\\
x,& 2 \le x <4\\
x^3+1,& x\geq 4
\end{cases}
\end{displaymath}
%---------------
\section{How to include Bibiliography automatically}
\end{defn}





\end{document}