#### SusanCoutu

##### New member

- Joined
- Sep 28, 2018

- Messages
- 4

A product sells for $3.50 currently and has a demand function of

p = 8000/q

Suppose manufacturing costs are increasing at a rate of 15% over time and the company plans to increase the price p at this rate as well. Find the rate of change of demand over time.

But when I differentiate this problem for time, I get:

dq/dt = -8000 * p^(-2) * dp/dt

Assuming p, the price, equals $3.50, and the rate of change of the price, dp/dt, equals 1.15 (15% increase), the answer I get is approximately -751, when my textbook is telling me it should be -343. Where am I going wrong?