\documentclass[12pt]{article}

\title{Finding root}
\author{zhouer}
\usepackage{amsmath}

\begin{document}
\maketitle

\section{M\"uller's method}

\begin{align*}
y_0 & = f(p_0)\\
y_1 & = f(p_1)\\
y_2 & = f(p_2)\\
\end{align*}

\begin{align*}
P(x) & = a(x - p_2)^2 + b(x - p_2)^2 + c\\
a & = \frac{(p_1 - p_2)(y_0 - y_2) - (p_0 - p_2)(y_1 - y_2)}{(p_0 - p_1)(p_0 - p_2)(p_1 - p_2)}\\
b & = \frac{(y_1 - y_2)(p_0 - p_2)^2 - (y_0 - y_2)(p_1 - p_2)^2}{(p_0 - p_1)(p_0 - p_2)(p_1 - p_2)}\\
c & = y_2\\
\end{align*}

\begin{align*}
p_{n + 1} = p_n - \frac{2c}{b + \text{(best choice of $\pm$)} \sqrt{b^2 - ac}}
\end{align*}

\section{Laguerre's method}

\begin{align*}
z_{n + 1} = z_n - \frac{n}{\frac{f'(z_n)}{z_n} + \text{(best choice of $\pm$)} \sqrt{(n - 1)\lbrace n[(\frac{f'(z_n)}{f(z_n)})'] - [\frac{f'(z_n)}{f(z_n)}]^2\rbrace}}
\end{align*}

\end{document}