# Is # x=3# a function?

##### 1 Answer

No. The equation

For one thing, it fails the vertical line test for functions at the value

#### Explanation:

A function maps

For a given

One way to express this condition is the vertical line test. Any vertical line must intersect the curve described by the equation at at most one point. If it does not intersect the curve at all, then the corresponding

In the case of the curve (vertical line) described by