this is a test here are some latex equations. \(a = b + c + \frac{1}{2}\)

some more eq \begin{align} k &= 2 \times \delta \
&= a + \mathbf{c} \end{align}

some more eq with align inside double dollar:

\[\begin{align} k &= 2 \times \delta \\ &= a + \mathbf{c} \end{align}\]