I'm new to LaTeX and I don't get where my error is. I'm running on Windows under Texmaker.
I only recieve this message : "! LaTeX Error: There's no line here to end."
\documentclass[12pt,a4paper]{article}
\usepackage[top=1cm,bottom=1cm,left=1cm,right=1cm]{geometry}
\usepackage{calc,multido,ifthen,bm}
\usepackage{graphics}
\usepackage[french]{babel}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{fancyhdr}
\usepackage{stmaryrd}
\usepackage{setspace}
\usepackage{dsfont}
\usepackage{enumitem}
\usepackage{natbib}
\usepackage{mathtools, amssymb,amsthm}
\usepackage{xcolor}
\title{Sujet 4}
\begin{document}
\section {Exercice 4 :} Soit $P(x) = x^3 - x + 1 $.
\\
txt
\\
\textcolor{blue} {On sait que $\alpha$, $\beta$, $\overline{\beta}$ sont les 3 racines du polynômes P. Donc P peut s'ecrire sous forme scindée :
$$P(x)=(x-\alpha)(x-\beta)(x-\overline{\beta})$$
$P(x)=(x^2-\beta x-\alpha x+\alpha \beta)(x-\overline{\beta})$ en développant
$$P(x)=x^3-\beta x^2 - \alpha x^2 +\alpha \beta x -\overline{\beta} x^2 +\beta \overline{\beta} x + \alpha \overline{\beta} x - \alpha \beta \overline{\beta}$$
Par identification, on obtient notamment :
\[-\alpha \beta \overline{\beta} = 1$$
$$\lvert \alpha \beta \overline{\beta} \rvert = 1$$
$$\lvert \alpha \rvert \lvert \beta \rvert \lvert \overline{\beta} \rvert = 1$$
$$\lvert \alpha \rvert \lvert \beta \rvert^2 = 1$$
$$\lvert \beta \rvert=\frac{1}{\lvert \alpha \rvert}\]
or $\alpha <-1$ donc $\lvert \alpha \rvert>1$
donc $\lvert \beta \rvert<1$}
\end{document}
There, I've done what you have said. I tried to run it but I had the same error in the same line.
Thank you for your help !
Best Answer
let me elaborate my comment (as supplement to samcarter answer):
\textcolor{<color>}{.....}
doesn't work over more paragraphs (as is your case). instead you should rather use switch\color{<color>}
and after end of colored part of document switch back with\color{black}
:by the way, Textmaker have nothing with your problem. it is only editor for
latex
.