Cannot put integral in Beamer presentation

Question

EDIT: I've found a solution thanks to this topic: beamer over miktex 2.9 is not working with math environment In any case, thanks to everyone who posted an answer!

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I'm struggling to put an integral in this presentation. Here's the code

\documentclass{beamer}
\usepackage{relsize}
\usepackage[english]{babel} 
\usepackage{amsmath,amsfonts,amsthm,bm}
\title{PCA for functional data}
\author{Carlo Schiano di Cola}
\date{21/07/2020}
\begin{document}
% [..]
\begin{frame}
\frametitle{Introduction}
Some concepts from the multivariate analysis can be imported in the functional context

\LARGE
x\textsubscript{i} $\rightarrow$ x(t)

$\mu$\textsubscript{i} $\rightarrow$ $\mu$(t)

$\Sigma$\textsubscript{ij} $\rightarrow$ v(s,t)

\begin{equation}
\int_{a}^{b} x(t)y(t)dt
\end{equation}
\end{frame}
 
\end{document}

The error I get says only that

MikTeX Compiler Driver did not succeed

Answer 1

I suggest you replace the inline-math formulas

x\textsubscript{i} $\rightarrow$ x(t)

$\mu$\textsubscript{i} $\rightarrow$ $\mu$(t)

$\Sigma$\textsubscript{ij} $\rightarrow$ v(s,t)

with

$x_i \to x(t)$

$\mu_i \to \mu(t)$

$\Sigma_{ij} \to v(s,t)$

Observe the use of (a) a single pair of $ delimiters per formula and (b) the _ ("underscore") character to initiate subscript-level material.