Question

How many points need to be removed from this graph so that it will be a function

Answer 1

3 points are needed for it to pass the vertical test

Explanation:

Answer 2

verteical line test
we should be able to draw a verteical (up to down) line and never hit any 2 points with the same line (line has to be paralell to y axis)

we have 3 pairs of points that are above each other (at x=-3 and x=1 and x=2)

we need to remove 3 points