f(x) has value 150 at x= 0
and 0 at x= 3
so d(f(x))/dt = slope = -150/3 = -50
the number of the people going.
step-by-step explanation:
the cost to buy one movie ticket is $7. if the total cost for the movie is a function of how many people go, then the input is : the number of the people going.