Stuck hopelessly on derivatives! Watch
The marginal cost function is 0.22222(q)^2 (no fixed costs)
On a graph, this means the cost curve intersects the price line at a quantity of 6, where profit is maximized. All good so far.
when I put this through the derivative method, I get a wacky answer
PROFIT = TR-TC
PROFIT = 8q - (0.22222(q)^2)
Differentiate using the power rule gives us .... -0.44444q +8
I then set the answer to zero, and the result for q comes out as
It should be 6! or damn near close! What am I doing wrong here?