Question

Which function is represented by this graph?

Answer 1

It's called a piecewise function, or more specifically, a step function

Answer 2

The second one

Answer 3

Solid, dark dots include that point. That means that it's greater than or equal to.
Open circles do not include the point. That means it's either greater than or less than.

Answer 4

Choice 3. because they all have the less then OR equal to signs. and all of them were equal to the points given.