Here is an example of a cloze card containing a latex formula

Formula: {{c1:: $f(x) = \frac{1}{\sqrt{x}}$}}

Unfortunately, the two curly braces after sqrt{x conflict with Anki's cloze syntax which also expects two }}. A simple solution would be to add a space between the two curly braces at runtime, right before creating the card in Anki, as shown below.

Formula: {{c1:: $f(x) = \frac{1}{\sqrt{x} }$}}