Nothing new is proved on this page. Every feature you are about to see is
something you already established without it.
cut
product
The table comes first. Fill it before you draw
anything.
product against cut
assessor's rule (62,500)
overcharge
Overlays
Turn on an overlay. Each one is a fact you proved algebraically; the page will say
which.
Demand a product
Drag the line. Count where it meets the curve. This is the only question the picture
answers faster than the algebra does.
The discipline of this page. For every feature you can see, you should be
able to name where you proved it: the ends at 0 and 500 from the factored form, the single
peak from 62500-(x-250)^2 and the fact that a square is never
negative, the mirror from the \pm d pairing, the number of
crossings from whether d^2 comes out positive, zero or negative.
If you can do that, the picture is a transcription and you have lost nothing by having
waited for it. If you cannot, go back — the picture is doing work it is not entitled to do.