00:01
We have a bunch more of these marginal revenue problems.
00:04
So again, as i mentioned, the revenue equals the revenue is a function of the number of items sold is the price of the items, which is the function of the number of items sold.
00:20
So this is the demand function times x.
00:23
And so r prime, or let's write it as drdx, is simply p of x.
00:34
Plus the p d x times x.
00:41
So in this case, the first case, we have p equals 100 or 400 minus x.
00:48
So the revenue is 400x minus x cube.
00:53
And the marginal revenue is then is 400 minus 2x.
00:57
Or we could have used this, get 400 here, and then this here would be minus x.
01:07
So we get 400 minus x and then another minus x, so 400 minus 2x.
01:13
We could use this form in two or just form the revenue and then take the derivative.
01:21
Next demand function is 500 minus x.
01:26
So the revenue would be 500x minus x cubed.
01:31
So the marginal revenue would be 500 minus 2x...