^What does this symbol mean in mathematics?

^What does this symbol mean in mathematics?

When discussing problems in Baidu, it is not convenient to write the power, so we use ^ instead, for example, x ^ 2 = x * X
If it is a mathematical expression, the top of the variable is usually a small perturbation

In mathematics, in x = log

Not equal to
LNX is a logarithm based on e, also called natural logarithm. The latter is not a logarithm because it has no base. Do you mean lgx? This is a logarithm based on 10, called common logarithm. Only natural logarithm and common logarithm can be omitted

Mathematical expectation e (E (x)) =?, e (E (y)) =?, e (E (x) e (y)) =?
E (E (x)) = e (x), e (E (y)) = e (y), e (E (x) e (y)) = e (x) e (y)

Yes!
The mean value of a constant is, of course, itself