Chose all the points that are located in quadrant IV

What is the name used to describe a graph where for some value of x, there exists 2 or more different values of y?

Aball is thrown from a height of 139 feet with an initial downward velocity of 15 ft/s. the ball's height h (in feet) after t seconds is given by the following. h=139-15t-16t^2 how long after the ball is thrown does it hit the ground? round your answer(s) to the nearest hundredth. (if there is more than one answer, use the "or" button.) t =

Find the value of x for which line a is parallel to line b