Freddie from Almond Hill school noticed that a decreasing quantity requires a negative first derivative, which allowed him correctly to match the equation for radioactive decay. Can you use these sorts of ideas to match all of the equations?

Pete Pederson from the Acadia Summer AP Calculus AB Workshop was the first to correctly identify the matches. Can you see how he did it?

A - W

B - X

C - V

D - Y

E - Z