Please help i really need this ill give brainliest if you answer it correctly

Select the number of ways in which a line and a circle can intersect

How is this equation completed? i cannot find any examples in the book.

An incoming airplane is x miles due north from the control tower at an airport. a second incoming airplane is y miles due east of the same control tower. the shortest distance between the two airplanes is z miles. which of the following functions would best model the situation above?