# Formeln¶

.. math::

(a + b)^2 = a^2 + 2ab + b^2

(a - b)^2 = a^2 - 2ab + b^2

\begin{align}\begin{aligned}(a + b)^2 = a^2 + 2ab + b^2\\(a - b)^2 = a^2 - 2ab + b^2\end{aligned}\end{align}
.. math::
:nowrap:

\begin{eqnarray}
y    & = & ax^2 + bx + c \\
f(x) & = & x^2 + 2xy + y^2
\end{eqnarray}

\begin{eqnarray} y & = & ax^2 + bx + c \\ f(x) & = & x^2 + 2xy + y^2 \end{eqnarray}
.. math:: e^{i\pi} + 1 = 0
:label: euler

Euler's identity, equation :eq:euler, was elected one of the most
beautiful mathematical formulas.

(1)$e^{i\pi} + 1 = 0$

Euler’s identity, equation (1), was elected one of the most beautiful mathematical formulas.