Question

Could I get some help with this question please:)

Demand function
128
------ +2
x^2

Quality demand x = 4

Find the price elasticity of demand for the demand function at the indicated x-value.

Answer 1

2^7 = 128; (1/2)^x=128; (1/2)^-7 = 2^7; x = - 7

(4/9)^x = 81/16 = (9/4)^2; x = - 2

(1/8)^x = 1/16 = (1/8)/2 = (1/2^3)/2 = 1/2^4); x = 4/3 ( the cube root of 8^4)