Blog #4

Well, this week went by pretty fast, and we are all still on Chapter 2. But section 2.3. I really don't understand the quotient rule that we just learned this week...I mean I understand how to use it but I'm having some problems with the actual plugging in and solving part of it. Anyways, I'll try to explain to the best of my ability the product and quotient rules. You have to use f(x) and g(x) in these formulas btw. The asterisk is a multiplication symbol btw. This is confusing btw.

Product Rule

d/dx [f(x)*g(x)] = f(x)*g'(x) + g(x)*f '(x)

Quotient Rule

d/dx [(f(x))/(g(x))] = (g(x)*f '(x) - f(x)*g'(x))/([g(x)]^2)

I'll give an example of the product rule, since I'm kinda rusty on the quotient rule.

Find the derivative of the product of (2x-x^2)(4+2x)

(2x-x^2)(2) + (4+2x)(2-2x)

Just FOIL this out.

4x - 2x^2 + 8 - 8x + 4x - 4x^2

Comes out to a simplified form:

-6x^2 + 8

That is the derivative, using the product rule.

As I said above, I am really bad on the quotient rule, so a few examples would be really nice lol. Thanks.