Question

identify if each graph is a function or is not a function.
a)
b)

Explanation:

Step1: Recall the vertical line test

A graph represents a function if and only if no vertical line intersects the graph more than once.

Step2: Analyze graph a)

For the green line (graph a), if we draw any vertical line, it will intersect the line at most once. So it passes the vertical line test.

Step3: Analyze graph b)

The red line (graph b) is a vertical line. A vertical line will intersect itself infinitely many times, and for a vertical line \(x = c\) (where \(c\) is a constant), there are infinitely many \(y\)-values for the same \(x\)-value. So it fails the vertical line test.

Answer:

a) is a function; b) is NOT a function