A) Demand function
price (x) demand (D(x))
4 540
3.50 810
D - 540 810 - 540
----------- = -----------------
x - 4 3.50 - 4
D - 540
----------- = - 540
x - 4
D - 540 = - 540(x - 4)
D = -540x + 2160 + 540
D = 2700 - 540x
D(x) = 2700 - 540x
Revenue function, R(x)
R(x) = price * demand = x * D(x)
R(x) = x* (2700 - 540x) = 2700x - 540x^2
b) Profit, P(x)
profit = revenue - cost
P(x) = R(x) - 30
P(x) = [2700x - 540x^2] - 30
P(x) = 2700x - 540x^2 - 30
Largest possible profit => vertex of the parabola
vertex of 2700x - 540x^2 - 30
When you calculate the vertex you find x = 5 /2
=> P(x) = 3345
Answer: you should charge a log-on fee of $2.5 to have the largest profit, which is $3345.
A binomial squared is written like

So, we have 
So, we want to complete the square 
We can add and subtract 9 to write

Step-by-step explanation:
cos A = 16/20 = 4/5
tan A = 12/16 = 3/4
sin A = 12/20 = 3/5
Answer:
y = -1/3x + 5
Step-by-step explanation:
-1/3 is the slope because the line goes down 1 unit and right 3 units.
The y-intercept is 5 because that is where the line crosses the y-axis.
42 brotha you gotta cut down the data set until you reach the median