Example
The supply for cookies follows the following equation: `Q_s = 10 + 2P`.
Solving for P:
$$ \begin{align*} Q_s &= 10 + 2P \\ 2P &= Q_s - 10 \\ P &= \frac{Q_s - 10}{2} \end{align*} $$ The inverse supply is `P = \frac{Q_s - 10}{2}`Question
The supply for bananas follows the equation `Q_s = 14 + 7 P`.
Find the inverse supply function.
Determine the price of bananas when the quantity supply is 42.
Let's transform the supply function into the inverse supply function.
$$ \begin{align*} Q_s &= 14 + 7 P \\ 7 P &= Q_s - 14 \\ P &= \frac{14 - Q_s}{7} \end{align*} $$The inverse supply function is `P = \frac{14 - Q_s}{7}`.
If the quantity supplied is 42, then
$$ P = \frac{14 - 42}{7} = 4 $$The price producers get for a banana is $4.