00:01
So we're given a revenue equation, and we know that the revenue equation is given to us in terms of x, the number of objects sold, apparently, is given by this.
00:18
And you may want to rewrite it like this, and now we want to find where this function is at a maximum.
00:33
So we want to find what the first derivative is, and set it equal to zero.
00:38
We know the derivative of a constant is zero.
00:41
And then we use our power rule here.
00:43
Well, really a chain rule.
00:45
And so we have negative 1 times negative 1 ,600.
00:48
We have 1 ,600.
00:50
And then we have x plus 8.
00:52
And we lower the power down.
00:54
And then we would multiply it by the derivative of that inner, but there is that derivative of that inner is 1.
01:01
And, oops, and i didn't, that was an x.
01:03
That's my mistake...