copy the following code (including the triple hyphens --- ) and paste it to your RMD. please pay attention to the indention in the YAML.

---
title: '<center>Slidy Presentation</center>'
author: "Cheng Peng"
date: '<img src="logo.png" width=100 length=100><br><br> West Chester University'
output: 
  slidy_presentation:
       font_adjustment: +1
       footer: 'Slidy presentation created using RMarkdown (modified from the default template for STA490 Capstone Statistics)'
       widescreen: yes
       self_contained: true
---