The demand equation is
.
is the price in dollars.
is the quantity sold of a certain product.
Solve
for
.
.
(a)
\The revenue
.
Substitute
in
.

Revenue
.
(b)
\The quantity sold of a certain product
.
Revenue
.

The revenue if
units are sold is
.
(c)
\The function
is a quadratic function.
Compare the function with standard form of a quadratic function.
\
.
Since
, the vertex is the maximum point on the parabola.
The revenue
is a maximum when the quantity sold of a certain product
is
.

Maximum revenue :
\
Maximum revenue is
(d)
\The price
.
Maximum revenue is
at
.
At
, the company charge to maximum price.
The maximum price,
\
should the company charge to maximize the revenue.
(e)
\Graph
and
are on the same Cartesian plane.
Find where the graphs intersects.
\
The graph is shown below :
\
The graphs intersect at
and 
From the graph the company should charge between
to earn at least 
in revenue.
\ \(a) Revenue
.
(b) The revenue if
units are sold is
.
(c) The maximum quantity is
and maximum revenue is
(d)
should the company charge to maximize the revenue.
(e) The company should charge between
to earn at least 
in revenue.