What is the price elasticity of demand? Imagine that the market demand function for packets of blue

Question:

What is the price elasticity of demand? Imagine that the market demand function for packets of blue cheese is specified as follows:

where Q_DC is for the quantity of blue cheese packets demanded and PC is for the price of blue cheese per packet. Evaluate the function when price is $2 per packet and explain why consumers may or may not be sensitive to changes in the price of blue cheese.