\bar{y}The symbol \bar{y} is used to denote a bar accent over the variable y. This is often used in mathematics and statistics to represent the mean or average of a set of values, or to indicate a complex conjugate in complex numbers.
Represents the mean of a set of values y_i.
\bar{y} = \frac{1}{n} \sum_{i=1}^{n} y_iIndicates that the mean value \bar{y} is a real number.
\bar{y} \in \mathbb{R}Represents the complex conjugate of a complex number z = x + iy.
z = x + i\bar{y}