Answer :
Answer:
Step-by-step explanation:
R = P * Q
Let's make differentiation for time (t)
dR/dt = (dP/dt)*Q + P*(dQ/dt)
dR/dt = (dP/dt)*30 + 15,000*2
The revenue starts to drop means dR/dt < 0
Then:
(dP/dt)*30 + 15,000*2 < 0
(dP/dt)*30 < -30,000
dP/dt < -1,000
Thus, the monthly revenue starts to drop when the price drops more than $1,000 per month.