Ive gotten this wrong once and i still dont get it

Look at the following graph of the given equation. determine whether the equation is a function. explain why or why not.

What is the area of a pizza with a radius of 40 cm leave the answer in terms of π to find your exact answer 40π cm² 1600π cm² 800π cm² 80π cm² π=pi

Acylinder and its dimensions are shown. which equation can be used to find v, the volume of the cylinder in cubic centimeters?