about cobb-douglas production function - 經濟

Suppose that the production function in operating is Cobb-Douglas with

diminishing returns but that there is a flow fixed cost.

Then the operating profit is p(theta)-f , where the multiplicative constant

is set at unity, theta>1 , and f is the flow fixed cost.

（There is no variable cost）

p is the product price.

My question is how to derive the profit equation p(theta)-f and

what the parameter theta is.

The result is cited form Dixit（1989）

" Entry and exit decision under uncertainty”.

Thanks!

--