Derivitive with ln - don't understand

[zeion]

Homework Statement

Differentiate the following:
y = ln(2x^2 - 2) / x^2 - 1

The Attempt at a Solution

The answer is y' = -ln(2x^2 - 2)(2x)(x^2 - 1)^-2 + 4x / 2x^2 - 2 (x^2 - 1)^-1

I understand all of it except 4x / 2x^2 - 2, how does ln(2x^2 - 2) derive into 4x / 2x^2 - 2?

 

[rock.freak667]

$$\frac{d}{dx}(ln(f(x))=\frac{f'(x)}{f(x)}$$

 

[zeion]

Oh okay, thanks, never seen that one before.

 

[Hurkyl]

Oh okay, thanks, never seen that one before.

If you look closely, you'll notice that's just the chain rule...

 

[zeion]

Really? How?

 

[mblack]

To see how it is the chain rule, think about what the derivative of ln x is.