00:01
For this problem, we are told that a company manufactures and sells x smartphones per week.
00:06
The weekly price demand and cost equations are p equals 500 minus 0 .5x and c of x equals 20 ,000 plus 135x.
00:14
For the first part, we are asked, what price should the company charge for the phones and how many phones should be produced to maximize the weekly revenue and what is the maximum weekly revenue? then for part b, we are asked, what is the maximum weekly profit and how much should the company charge? for the phones, how many phones should be produced to realize the maximum weekly profit.
00:37
Keep in mind, profit versus revenue.
00:40
So, for part a regarding the price, and specifically the weekly revenue, we know that the revenue is going to equal the price times the number of units sold.
00:54
So our revenue is going to actually equal x times 500 minus 0 .5x.
01:05
Which then means we can expand this out as negative 0 .5x squared plus 500x.
01:14
One second here.
01:15
Now to maximize the weekly revenue, we want to take the derivative of the revenue with respect to the number of units sold.
01:22
So that is going to give us, so we'll have negative 0 .5 times 2, so that's just going to be negative 1x plus 500.
01:32
So we want to figure out how many units sold will bring this to 0.
01:37
Obviously that is going to be just when x equals 500.
01:42
We'll have that the derivative of the revenue with respect to units sold is going to be zero.
01:49
And we can tell, you know, this is a parabola.
01:53
So up here is going to be the maximum.
01:55
That's the turning point where the derivative is zero.
01:58
So to figure out what the maximum weekly revenue then will be, we just plug that back in...