Which event below is independent of event A?
A: You get to work on time.
Your alarm goes off.
A It's snowing outside.
B You remember to pick up C milk on the way home.
D There are no accidents on the road.

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?