If the demand function for q units of a commodity at p$ per unit is given by , find the rate of change of quantity with respect to price when . Round your answer to three decimal places.
A)0.017
B)-0.017
C)0.009
D)-0.011
E)0.005

Question

If the demand function for q units of a commodity at p$ per unit is given by  , find the rate of change of quantity with respect to price when  . Round your answer to three decimal places.
A)0.017 
B)-0.017 
C)0.009 
D)-0.011 
E)0.005

Quizplus · Accepted Answer

We need to find $\frac{dq}{dp}$ when $p=4$. 
Using the power rule and substituting $p=4$, we get
$$\frac{dq}{dp} = 0.3p^{-0.7} = 0.3(4)^{-0.7} = -0.0171$$
Rounding this to three decimal places, we get $\boxed{	extbf{(B) }-0.017}$.

If the Demand Function for Q Units of a Commodity