This question is from Dixit book- Optimization theory Please try your best to solve it

Marimum Value Functions 67 Exercises Exercise 5.1: The Cobb-Douglas Cost Function Consider a production function y -A I (5.22) j=1 where y is output, the r, are inputs, and A and the a, are positive constants. Let w = (w; ) be the vector of input prices, and show that the minimum cost of producing a given output level y is C(w, y) = B(y/A) 1/8 ( w;/a, )a;18, (5.23) j=1 where B = _, aj. If 3