Once again, if this looks completely unfamiliar to you or you're a little shaky, go watch the videos, do the practice on the power rule or the product rule, or in this case, the quotient rule. And the quotient rule is a little bit more involved and we have practice and videos on that. And I always have mixed feelings about it, because if you don't remember the quotient rule, you can usually, or you can always convert a quotient into a product by expressing this thing at the bottom as f of x, or by expressing this as f of x times g of x to the negative one, so you could take the derivative with a combination of the products and this fourth rule over here, the chain rule. And if any of this is looking unfamiliar again, don't watch this video. This video is for folks who are familiar with each of these derivative rules or derivative techniques and now wanna think about, well, what are strategies for deciding when to apply which? So let's do that. Let's say that I have the expression, let's say I'm interested in taking the derivative of x squared plus x minus two over x minus one.