# Thread: can you guys help me on a question

1. ## can you guys help me on a question

If the quantity supplied of a commodity Qs (measured in tonnes per week) is a function of its price P (measured in £ per tonne) such that:
Qs = 2*P-8

a) Find the inverse function, in other words generate an equation for P in terms of Qs. (3 marks)
b) Identify the maximum price level P at which the quantity supplied Qs is zero. (2 mark)

2. Originally Posted by shakir007
If the quantity supplied of a commodity Qs (measured in tonnes per week) is a function of its price P (measured in £ per tonne) such that:

Qs = 2*P-8

a) Find the inverse function, in other words generate an equation for P in terms of Qs. (3 marks)
b) Identify the maximum price level P at which the quantity supplied Qs is zero. (2 mark)
a) If $\displaystyle Q_s = 2P - 8$

$\displaystyle Q_s + 8 = 2P$

$\displaystyle P = \frac{1}{2}(Q_s + 8)$

$\displaystyle P = \frac{1}{2}Q_s + 4$.

b) If $\displaystyle Q_s = 0$ you have

$\displaystyle P = \frac{1}{2}\cdot 0 + 4$

$\displaystyle P = 4$.