Occosionally I like to use a formula, but there are some symbols which I do not know how to make with the editor. And I know it is possible, because I see these symbols in other posts.

Some symbols I would like to use and don't know how to make are: exponents, indices, the square root sign, Greek letters, the integral sign, the inverted delta (or nabla) sign, the Poincaré square sign and the curved d's (partial differentials).