Determine whether the equation defines y as a function of x.
-$$x ^ { 2 } + y ^ { 2 } = 9$$
A) $y$ is a function of $x$
B) $y$ is not a function of $x$

Question

Quizplus · Accepted Answer

The equation $x^2 + y^2 = 9$ represents a circle with radius 3 centered at the origin. For some values of $x$, there are two different $y$ values (one positive and one negative) that satisfy the equation. This violates the definition of a function, which requires each input to have exactly one output.

Determine Whether the Equation Defines Y as a Function of X