You can
put this solution on YOUR website!
to "solve" this - as a purely theoretical question, we want to know where the curve crosses the x-axis, ie where y is zero. In your question you are using D instead of y, so where is D=0...
and re-arranging gives
this does not factorise, so use the quadratic formula.
This produces 2 answers for p, namely p=0.465 and p=103.535.
Now any quadratic is a symmetrical curve so, the maximum lies mid-way between these 2 values... namely at (0.465+103.535)/2 --> p=52.
So, the price at which it sells the maximum number of drills is $52
This corresponds to
drills
drills
D = 24096 drills
As for a graph... pick a few values of p, put each into the equation as i did and find corresponding values of D then plot them.
jon.
