Suppose that the demand function for good Z is given as a non-linear function: Qd(P) = aP^b, where a>0 and b<0 are constants and P is the price of good Z.
a) Find price elasticity of demand for Z when P = 1.
b) Find price elasticity of demand for Z when P = 2.
Your answer at (a) and (b) should be the same.