00:01
So we want to find the profit function given this marginal function here.
00:10
The first thing we're going to have to do is figure out how the marginal function relates to the profit.
00:16
So remember that marginal is really just talking about a very small change in something.
00:24
And the way that we describe very small changes in calculus is with the derivative.
00:30
So what this is really saying is look at we're given the derivative of the profit function.
00:40
So if i want to find the profit function from the marginal, we'll want to take the antiderivative or integrate p prime of x here.
00:54
Let's go ahead and do that.
01:02
So it's not really willing to cooperate.
01:04
So i'll just rewrite again.
01:06
P prime of x is equal to 3 square root of x plus 2.
01:15
So we want to integrate this so we can find our profit function.
01:25
So i'll just go ahead and integrate each side of this function with respect to x.
01:36
So integrating p prime of x will just give us p of x.
01:42
So our profit, and then if we want to take the integral of 3 square root of 2 x plus 2, well first we can go ahead and rewrite this so we can put it into terms of things we do know the integral of.
02:04
So remember the square root of x is really x to the one half power, and any time we have a constant being multiplied, or just a constant, it's really being multiplied by that variable to the zero of power.
02:21
So this will be two instances of power rule.
02:24
So the first thing we want to do is go ahead and use the sum and scalar property of integration and rewrite this as.
02:33
So three, so i'll just go ahead and rewrite the equation first, plus 2 x to 0, and then distribute the integration with our variables.
02:48
And now we can apply the power rule.
02:52
So it will be 3, and then power rule for antiderivatives.
02:59
So it's 1 half, and then i add a power of 1, and then divide by the new power, so 1 half plus 1 is 3 halves.
03:09
Then i add some constant c1...