A competitive firm has the short-run cost function c(y)= y^3 - 2y^2 + 5y +6 . Write down equations for:
a. The firm's average variable cost function
b. The firm's marginal cost function
c. At what level of output is average variable cost minimized?
d. Graph the short-run supply function for this firm, being careful to label the key points on the graph with the numbers specifying the exact prices and quantities at these points.