00:01
So we're given this demand function here and this x value.
00:05
So we're trying to find here is the price elasticity of demand along this x value here.
00:12
To do that, we have to do p over x divided by p prime.
00:16
And so plugging that in, we get 20 minus 0 .02x divided by x divided by negative 0 .02, and we take the derivative of p.
00:29
Then from here, we're going to plug in 560.
00:31
So we got 20 minus 0 .02 times 560 here.
00:40
It's going to be divided by 560, divided by negative 0 .02.
00:46
And so then that's going to be approximately 0 .786, which we know is less than 1.
00:56
That means it's – oh, actually, that's all we need for that first part.
01:10
So then for part b, being asked to find the values of x and p that would maximize the revenue.
01:20
And so to get the revenue function, we do x times b.
01:23
Which is equivalent to 20x minus 0 .02x squared.
01:30
To maximize the revenue, we'd have to take the derivative, so let's go ahead and do that.
01:34
We do 20 minus 0 .04x, then we set that equal to 0.
01:39
So that means that 20 equals 0 .04x...