Question

Explain why each graph is or isnt a function

Answer 1

only c is a function.

a, b, and d all fail the vertical line test, meaning their x values can have multiple outputs.

Answer 2

B and C are functions but A and D are not

Explanation:

Vertical line testing. You draw a vertical line. If the vertical lines passes through one line, its a function. It it passes through more than one line, its not. Or in other words, each input (x-value) has its own output (y-value)