Positioning textblock in LaTeX Beamer

There are times that we wanted to position an equation on the top right of the slide in beamer. The easiest way to do it is to use two packages: textpos and eso-pic. textpos package positions the textblock, while eso-pic sets up a grid system on the slides.

We include the two packages with options.

\usepackage[absolute,overlay]{textpos}
\usepackage[texcoord,
grid,gridcolor=red!10,subgridcolor=green!10,gridunit=pt]
{eso-pic}

To position a textblock, use the options \begin{textblock}{WIDTH}(XCOORDINATE,YCOORDINATE). Here is an example.

\begin{textblock*}{10pt}(150pt,1pt)
\small
\begin{equation*}
    \mathbf {H} = \frac{1}{2}\left( - \omega_{\mathrm{m}} + {\color{red}\delta \lambda(x)} \cos 2\theta_{\mathrm{m}} \right) \sigma_3 - \frac{  {\color{red}\delta \lambda(x)}  }{2} \sin \theta_{\mathrm{m}} \sigma_1
\end{equation*}
\end{textblock*}