This is my code
\documentclass[12pt,a4paper]{book}
\renewcommand{\baselinestretch}{1.5}
\begin{document}
\include{Chapter1}
\end{document}
I have please a question:
I would change the line spacing (1.5 --> 1.0) of a page inside the document and not the entire document and the size of the words, how can I do please?