F(n)=2n to the third power -5n ; find f(2)

A20? -foot ladder is placed against a vertical wall of a? building, with the bottom of the ladder standing on level ground 19 feet from the base of the building. how high up the wall does the ladder? reach?

What is the average rate of change for this function for the interval from x=2 to x=4 ?

F(n + 1) = f(n) – 8. if f(1) = 100, what is f(6)?