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Derivative of a fraction?

  • Thread starter lreichardt
  • Start date
How do I take the derivative of

f(x)=ln[x/(x-1)]?

Thanks!
 

Answers and Replies

tiny-tim
Science Advisor
Homework Helper
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Welcome to PF!

Hi lreichardt! Welcome to PF! :smile:

Just use the chain rule: derivative of ln, times the derivative of x/(x-1). :smile:
 
so, (x/1)(quotient rule of x/(x-1)? =

(x/1)(-x/x-1)=-x^2/x-1
 
tiny-tim
Science Advisor
Homework Helper
25,789
249
ooh dear …

better go the easy way … simplify it first …

ln(x/(x-1)) = ln(x) - ln(x-1) … now differentiate! :smile:
 
1
0
Chain rule = The difference of the derivative of the "Outer" and derivative of the "Inner", put simply.
 
Thanks all, figured it out.
 

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