Faq/Math/002/en

How do I get * as a superscript? Using x^* produces an error.
The problem is that  is a binary operator, which must be between two expressions. For x*, use one of these sets of markup:

This answer applies to other binary operators such as ∙ (cdot) and ÷ (div).

Some symbols are unary operators, such as. These only require an expression on the right, not the left. To use these symbols, use one of these sets of markup:

If you regularly use binary or unary operators as superscripts, you may want to create a userdefined symbol and then your markup would be. See How do I use a symbol not provided in Math's Catalog of characters?