Which of the following equations does not define y as a function of x ?
A) $y = 7 x + 2$
B) $y = | x - 1 |$
C) $x = | y |$
D) $y = 2 x ^ { 2 } - 4$

Question

Quizplus · Accepted Answer

In equation C, there are two possible values of y for certain values of x (one positive and one negative), which violates the definition of a function where each x value corresponds to only one y value. The other equations all define y as a function of x.

Which of the Following Equations Does Not Define Y as a Function