The demand equation is just what they call the equation that's always given to you in business calculus problems. The weird thing is that it's usually given to you as x(p) - demand (x) as a function of price (p). So this video explains why they're doing that, and what you'll want to do to fix it so that you can use it to calculate marginal revenue and profit.
What Is Marginal Cost, Marginal Revenue & Marginal Profit?
This whole "marginal" thing in economics is kind of wacky, but it's the key to writing really confusing business calculus test questions (lol). It's also, one would assume, important in actual business, since it allows you to apply calculus to business goals like maximizing the profit your company makes.
Marginal Cost Examples
In the previous video we talked about what marginal cost means. In this video we'll learn how to calculate the marginal cost when you're given a function for cost such as C(x)=5000+34.5x. Using the derivative to calculate marginal cost gives you the "approximate marginal cost". The next video covers "exact marginal cost".
Exact Marginal Cost vs Approximate Marginal Cost
In this video we cover how to calculate the exact marginal cost, where you don't use a derivative but instead use C(x) and C(x+1). Also explained is the difference between exact marginal cost and approximate marginal cost and how to compare them, which is the most common type of question you'll see about these.
Graphical analysis of Marginal Cost, Revenue & Profit
In business calculus, teachers often want you to be able to look at a graph and pick out certain important points, like where profits are maximized. So in this video we don't use any numbers, instead looking at the types of qualitative questions they can ask you about graphs of profit, cost and revenue.
Revenue & Marginal Revenue
This video covers business calculus calculations around the topic of revenue, which you can calculate by multiplying demand and price.
Marginal Profit & Maximum Profit Calculations
All the business calculus videos about marginal revenues and costs have been building to this point, so that we can use the derivative of the profit function to figure out exactly how many widgets your factory should make in order to maximize the amount of profit. Capitalism!
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