# Aligning and specifying font size in LaTeX equations

I have specified 3 equation in tex file,

The font size of contents in each equation in the align environment appears to be different.Also, not all equations all aligned in the same way. Is there a way to specify same font size for all equations and align it in a nice way?

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage{mathptmx}
\usepackage{amsmath}
\usepackage{makecell}

\title{Table}
\author{xx }
\date{May 2019}

\begin{document}

\vspace{1cm}
\large \textbf{1-D   equation:}\\
\begin{align*}
\large{ \hspace{2cm}\frac{\partial A}{\partial t} = 2\frac{\partial A}{\partial x}}
\end{align*}

\large \textbf{Equation 2:}\\
\vspace{1cm}
\small{ \textbf{Number = 2}}\\
\begin{align*}
\large{ X = CS = \frac{R}{8}\Delta G}
\end{align*}
\vspace{0.5cm}
\large \textbf{Equation 3}\\
\vspace{0.5cm}
\small{ \textbf{Movement}}\\
\begin{align*}
\Large{\hspace{3cm}D_{q} = \frac{\big(\frac{CS}{40}\big)^2.5}{1256}}
\end{align*}
\end{document}


EDIT: Updated code after making the changes suggested in the comment. The font size issue is resolved now. The problem is with the alignment of text and equations.

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage{mathptmx}
\usepackage{amsmath}
\usepackage{makecell}

\title{Table}
\author{xx }
\date{May 2019}

\begin{document}

\vspace{1cm}
\large \textbf{1-D   equation:}\\
\begin{align*}
{\large \hspace{2cm}\frac{\partial A}{\partial t} = 2\frac{\partial A}{\partial x}}
\end{align*}

{\large \textbf{Equation 2:}}\\
\vspace{1cm}
{\small \textbf{Number = 2}}\\
\begin{align*}
\large X = CS = \frac{R}{8}\Delta G
\end{align*}
\vspace{0.5cm}
{\large \textbf{Equation 3}}\\
\vspace{0.5cm}
{\small \textbf{Movement}}\\
\begin{align*}
{\large\hspace{3cm}D_{q} = \frac{\big(\frac{CS}{40}\big)^2.5}{1256}}
\end{align*}
\end{document}

• Commands like \large or \small don't take an argument, they are switches that make their effect last until the currently active group is closed. Use {\large ...} etc. to limit the scope instead. – siracusa May 21 at 4:10
• There are several other markup problems: 1) You shouldn't use \ as newlines, use \par or an empty line instead. 2) align* is meant to align several equations at a common position, you are only using a single equation each. Perhaps you want equations instead? 3) There is a lot of manual spacing. Especially the \hspace in the align blocks makes the alignment look weird. For structuring your document, you should better use \section, \subsection etc. commands and remove the manual spacing. – siracusa May 21 at 4:27

You should adjust font sizes globally, for example via an option to the document class. Headings are best done with standard commands for consistency of style and spacing. You need to issue \maketitle to get your title and author printed.

\documentclass[12pt]{article}

\usepackage{mathptmx}
\usepackage{amsmath}

\title{Table}
\author{xx}
\date{May 2019}

\begin{document}
\maketitle

\section*{1-D   equation:}
\begin{equation*}
\frac{\partial A}{\partial t} = 2\frac{\partial A}{\partial x}
\end{equation*}

\section*{Equation 2:}
\subsection*{Number = 2}
\begin{equation*}
X = CS = \frac{R}{8}\Delta G
\end{equation*}

\section*{Equation 3:}
\subsection*{Movement}

\begin{equation*}
D_{q} = \frac{\bigl(\frac{CS}{40}\bigr)^2.5}{1256}
\end{equation*}
\end{document}

• Thanks a lot. I'd like to know if there a way to align all = symbol,in the 3 equations, at the same position. – Natasha May 22 at 3:10
• See tex.stackexchange.com/q/197698/15925 (place & before = instead at the beginning of the line) – Andrew Swann May 22 at 6:08