Calculate the demand elasticity

Demand for the book “One Trick Pony” by Diane Nguyen is given by 𝑄 = 56−2𝑃 where 𝑃 is the price in
USD and 𝑄 are the demand in millions of copies.

a) Draw a diagram of the quantity demanded where you have 𝑃 on the vertical y-axis and 𝑄 on it
horizontal x-axis.

b) Calculate the demand elasticity when 𝑃 = 14. You must present your answer based on the formula for elasticity.

c) There is a simpler explanation for why you got exactly the value you got in the previous sub-task.
What is it?

d) How should the figure you obtained in sub-task (b) be interpreted? Explain in words.