A manufacturer incurs the following costs in producing x
waffle irons in one day for 0 < x < 100 :
fixed costs, 310 dollars; unit production cost, 21 dollars per
waffle iron; equipment maintenance and repairs, 0.06 x^2
dollars.

(A) Find the average cost function

(B) List all the critical values of

(C) Use interval notation to indicate where

** Note: ** Use 'INF' for

Increasing:

(D) Use interval notation to indicate where

Decreasing:

(E) List the

(F) List the

You can earn partial credit on this problem.