1/4+1/3?!?!?!?!please help me QUICK its for my homework its due in a couple of hours!

Using the graph below, select all statements that are true. a. f(0.6)=0 b. f(-3.2)=-3 c. f(5.1)=5 d. this is the graph of the greatest integer function. e. this graph is one-to-one.

[10 points, algebra 2]according to my answer key the restrictions are -1 and 4. but why not positive 1?

What is the distance between point a and b