1. Problem: Simplify and understand the expression $\sqrt{y}$, which represents the square root of $y$. 2. Formula: The square root of a number $y$ is a value that, when multiplied by itself, gives $y$. It is written as $\sqrt{y}$. 3. Important rule: $\sqrt{y^2} = |y|$, meaning the square root of $y$ squared is the absolute value of $y$. 4. Explanation: The square root symbol $\sqrt{\ }$ is used to denote the principal (non-negative) square root. 5. In Kurdish, the square root symbol looks the same as in standard mathematical notation, so $\sqrt{y}$ is written the same way. 6. Final answer: The expression $\sqrt{y}$ is the principal square root of $y$ and is written as $\sqrt{y}$.