# Thread: deriviative using log rules

1. ## deriviative using log rules

I am having some trouble remembering how to work out derivative using log rules.

How would I solve the following

d/dx (ln x^4 / x^5+1)

2. Originally Posted by gammaman
I am having some trouble remembering how to work out derivative using log rules.

How would I solve the following

d/dx (ln x^4 / x^5+1)
Well, a "log rule" you could use is that ln(x^4)= 4 ln x. You want to differentiate 4 ln(x)/(x^5+1) using the quotient rule and the fact that the derivative of ln(x) is 1/x.

3. Ok so what would the answer be. (By the way, I am supposed to use the rules for "The Natural Log").