Determine whether the equation defines y as a function of x.
-$$x + y ^ { 2 } = 4$$
A) $y$ is a function of $x$
B) $y$ is not a function of $x$

Question

Quizplus · Accepted Answer

For a given value of $x$, there can be two different values of $y$ that satisfy the equation $x + y^2 = 4$, because squaring a number gives a positive result whether the original number is positive or negative. This means that for some values of $x$, there are two corresponding values of $y$, which violates the definition of a function where each input should have exactly one output.

Determine Whether the Equation Defines Y as a Function of X