00:01
Okay, so first let's understand the context of this.
00:04
What's the context of the situation? well, suppose the cost in airing x television commercials during a super bowl is given by this function.
00:14
First, i want to find the marginal cost of the function.
00:16
What is marginal cost? well, recall that marginal cost is the rate of change of the cost.
00:23
So rate of change applies the first derivative.
00:25
So first let's find the first derivative at x.
00:28
Derivative 150 is 0.
00:31
Derivative of 2 ,250x is just that number minus 0 .02, bring down that 2, 0 .01x.
00:41
And let's say i want to find the marginal cost how fast it's increasing at 4.
00:45
So let's just plug in 4 into this function, 2 ,500 minus 0 .01 times 4.
00:52
So what this implies is that my marginal cost when i have four television commercials is going to be 2 ,249 and 96 cents.
01:10
So what this is saying is if i had a fifth super bowl commercial, then the additional cost would be $2 ,249...