Posted by sonia on .
Our professor gave us a exercise to do for fun where he said to derive profit=PQ(P,A)C(Q(A))A (note Q is a function of A both for revenue and cost)
the answer I came up with is profit= Pdq/da Cqfq/da1
=Pdq/da (d+c/dq)(dq/da)
Im not sure if I am right please help.

microecon 
economyst,
I'm having a trouble with your notation. This Jiskha site has mucho trouble in expressing mathmatical equations. (where did your "f" come from?)
That said, this is more of a calculus question. MR is the first derivitive of total revenue, so Pdq/da looks corret. MC is the first derivitive of the cost function. Here use the chain rule. Set MRMC=0 and tada you have your maximum profits equation.
I hope this helps. Lotsa luck.