Intégrez vos formules LaTeX dans vos posts entre $$ ... $$ comme dans l'exemple suivant :
$$ \left( \sum_{k=1}^n a_k b_k \right)^2 \leq \left( \sum_{k=1}^n a_k^2 \right) \left( \sum_{k=1}^n b_k^2 \right) $$
Pour les changements de lignes, utilisez impérativement \newline au lieu de \\, comme dans :
$$ \begin{aligned} \dot{x} & = \sigma(y-x) \newline \dot{y} & = \rho x - y - xz \newline \dot{z} & = -\beta z + xy \end{aligned} $$
Pour inclure vos formules dans le texte, utilisez ou $. exemple :
$\LaTeX$
Les exemples qui suivent sont issus de la page d'exemples de Mathjax.
The Lorenz Equations
$$
\begin{aligned}
\dot{x} & = \sigma(y-x) \newline
\dot{y} & = \rho x - y - xz \newline
\dot{z} & = -\beta z + xy
\end{aligned}
$$
The Cauchy-Schwarz Inequality
$$ \left( \sum_{k=1}^n a_k b_k \right)^2 \leq \left( \sum_{k=1}^n a_k^2 \right) \left( \sum_{k=1}^n b_k^2 \right) $$
A Cross Product Formula
$$
\mathbf{V}_1 \times \mathbf{V}_2 = \begin{vmatrix}
\mathbf{i} & \mathbf{j} & \mathbf{k} \newline
\frac{\partial X}{\partial u} & \frac{\partial Y}{\partial u} & 0 \newline
\frac{\partial X}{\partial v} & \frac{\partial Y}{\partial v} & 0
\end{vmatrix}
$$
The probability of getting \(k\) heads when flipping \(n\) coins is
\[P(E) = {n \choose k} p^k (1-p)^{ n-k} \]
An Identity of Ramanujan
$$
\frac{1}{\Bigl(\sqrt{\phi \sqrt{5}}-\phi\Bigr) e^{\frac25 \pi}} =
1+\frac{e^{-2\pi}} {1+\frac{e^{-4\pi}} {1+\frac{e^{-6\pi}}
{1+\frac{e^{-8\pi}} {1+\ldots} } } }
$$
A Rogers-Ramanujan Identity
\[ 1 + \frac{q^2}{(1-q)}+\frac{q^6}{(1-q)(1-q^2)}+\cdots =
\prod_{j=0}^{\infty}\frac{1}{(1-q^{5j+2})(1-q^{5j+3})},
\quad\quad \text{for $|q|<1$}. \]
Maxwell's Equations
$$
\begin{aligned}
\nabla \times \vec{\mathbf{B}} -\, \frac1c\, \frac{\partial\vec{\mathbf{E}}}{\partial t} & = \frac{4\pi}{c}\vec{\mathbf{j}} \newline \nabla \cdot \vec{\mathbf{E}} & = 4 \pi \rho \newline
\nabla \times \vec{\mathbf{E}}\, +\, \frac1c\, \frac{\partial\vec{\mathbf{B}}}{\partial t} & = \vec{\mathbf{0}} \newline
\nabla \cdot \vec{\mathbf{B}} & = 0
\end{aligned}
$$
Finally, while display equations look good for a page of samples, the ability to mix math and text in a paragraph is also important. This expression \(\sqrt{3x-1}+(1+x)^2\) is an example of an inline equation. As you see, MathJax equations can be used this way as well, without unduly disturbing the spacing between lines.