How to write dot product (a ⋅ b) in LaTeX?

In mathematics, a dot product is an algebraic equation commonly used in a vector. No package is required to write this in Latex.

Do not use simple dot

If you use \cdot, the default command of latex, it will be printed in the document, but some people use the . button on the keyboard, in which case the problem is shown below.

\documentclass{article}
\begin{document}
   \[ \vec{a} . \vec{b} \]
   \[ \textbf{A} . \textbf{B} \]
   \[ \vec{A} . \hat{B} \]
\end{document}

Output :

cdot command is best practice

As you can see in the example above, the output doesn’t look very professional for using the . button on the keyboard, so it would be best practice if you use the \cdot command.

\documentclass{article}
\usepackage{amsmath}
\begin{document}
   \[ \vec{a} \cdot \vec{b} = |\vec{a}||\vec{b}|\cos\theta \]
   \[ \textbf{A} \cdot \textbf{B}=|\textbf{A}||\textbf{B}|\cos\theta \]
   \[ \vec{A} \cdot \hat{B} = |A||B|\cos\theta \]
   \[ \frac{\textbf{a}\cdot\textbf{b}}{||\textbf{b}||}=||\textbf{a}||\cos\theta \]
   \[ \begin{bmatrix} a\\ b\\ c \end{bmatrix} \cdot \begin{bmatrix} x\\  y\\ z \end{bmatrix} \]
\end{document}

Output :