Example
The demand for cookies follows the following equation: `Q_D = 10 - 2P`.
Solving for P:
$$ \begin{align*} Q_D &= 10 - 2P \\ 2P &= 10 - Q_D \\ P &= \frac{10 - Q_D}{2} \end{align*} $$The inverse demand is `P = \frac{10 - Q_D}{2}`
Question
The demand for cookies follows the equation `Q_D = 120 - 15 P`.
What is the expression of the inverse demand function?
Let's transform the demand function into the inverse demand function.
$$ \begin{align*} Q_D &= 120 - 15 P \\ 15 P &= 120 - Q_D \\ P &= \frac{120 - Q_D}{15} \end{align*} $$The inverse demand function is `P = \frac{120 - Q_D}{15}`.