Determine if the equation specifies a function with independent variable x. If so, find the domain. If not, find a value of x
to which there corresponds more than one value of y.
-
A) A function with domain R
B) Not a function; for example, when x = 0, y = ±7

Question

Determine if the equation specifies a function with independent variable x. If so, find the domain. If not, find a value of x
 to which there corresponds more than one value of y.
-
A) A function with domain R 
B) Not a function; for example, when x = 0, y = ±7

Quizplus · Accepted Answer

The equation given does not specify a function with independent variable x because there are values of x (such as x=0) that correspond to more than one value of y. Specifically, when x=0, y can be either 7 or -7. Thus, this equation violates the vertical line test, which is the test used to determine if a graph represents a function. The equation does not specify a function because for x = 0, there are two values of y (7 and -7). Therefore, it fails the Vertical Line Test and is not a function.

Determine If the Equation Specifies a Function with Independent Variable