这是一道作业题，马上要交了，实在想不出来，请大家指点，本人愚钝，希望能给出详细的解答，先谢过啦。

An industry consists of a large number of firms, each of which has a cost function of the form

c(w₁,w₂,y)=(y²+1)w₁+(y²+2)w₂

(1)Find the average cost curve of a firm and describe how it shifts as the factor price ratio w₁/w₂ changes

(2)Find the short-run supply curve of an individual firm

(3)Find the long-run industry supply curve

(4)Describe an input requirement set for an individual firm