1. The problem is to understand the square root function and its properties. 2. The square root of a number $x$ is a value $y$ such that $$y^2 = x$$. 3. Important rules: - The square root function is defined for $x \geq 0$ in the real numbers. - The principal square root is always non-negative. 4. For example, $$\sqrt{9} = 3$$ because $$3^2 = 9$$. 5. The square root function can be written as $$y = \sqrt{x}$$. 6. This function is increasing and its graph starts at the origin $(0,0)$ and rises slowly to the right. 7. The domain is $[0, \infty)$ and the range is also $[0, \infty)$. Final answer: The square root function is $$y = \sqrt{x}$$ which gives the non-negative root of $x$ for $x \geq 0$.