What square root best approximates the point on the graph?

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.

If you answer right ill give brainliest, : )

What is the radius of the cone in the diagram? round your answer to the nearest whole number