Determine whether the equation defines $y$ as a function of $x$ \[ x=y^{2} \] Does the equation define $y$ as a function of $x$ ? Yes No

Step 1 ：Determine whether the equation defines $y$ as a function of $x$ for the equation $x=y^{2}$.

Step 2 ：In order for an equation to define y as a function of x, each x value must correspond to exactly one y value.

Step 3 ：In the given equation, $x=y^{2}$, for each positive x value, there are two corresponding y values (one positive and one negative).

Step 4 ：Therefore, the equation does not define y as a function of x.

Step 5 ：\(\boxed{\text{No, the equation does not define } y \text{ as a function of } x}\)