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Derivative of (x-1)/(ln(x-1)/(x-1))

Function f() - derivative -N order at the point
v

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The solution

You have entered [src]
   x - 1    
------------
/log(x - 1)\
|----------|
\  x - 1   /
x11x1log(x1)\frac{x - 1}{\frac{1}{x - 1} \log{\left(x - 1 \right)}}
(x - 1)/((log(x - 1)/(x - 1)))
Detail solution
  1. Apply the quotient rule, which is:

    ddxf(x)g(x)=f(x)ddxg(x)+g(x)ddxf(x)g2(x)\frac{d}{d x} \frac{f{\left(x \right)}}{g{\left(x \right)}} = \frac{- f{\left(x \right)} \frac{d}{d x} g{\left(x \right)} + g{\left(x \right)} \frac{d}{d x} f{\left(x \right)}}{g^{2}{\left(x \right)}}

    f(x)=(x1)2f{\left(x \right)} = \left(x - 1\right)^{2} and g(x)=log(x1)g{\left(x \right)} = \log{\left(x - 1 \right)}.

    To find ddxf(x)\frac{d}{d x} f{\left(x \right)}:

    1. Let u=x1u = x - 1.

    2. Apply the power rule: u2u^{2} goes to 2u2 u

    3. Then, apply the chain rule. Multiply by ddx(x1)\frac{d}{d x} \left(x - 1\right):

      1. Differentiate x1x - 1 term by term:

        1. The derivative of the constant 1-1 is zero.

        2. Apply the power rule: xx goes to 11

        The result is: 11

      The result of the chain rule is:

      2x22 x - 2

    To find ddxg(x)\frac{d}{d x} g{\left(x \right)}:

    1. Let u=x1u = x - 1.

    2. The derivative of log(u)\log{\left(u \right)} is 1u\frac{1}{u}.

    3. Then, apply the chain rule. Multiply by ddx(x1)\frac{d}{d x} \left(x - 1\right):

      1. Differentiate x1x - 1 term by term:

        1. Apply the power rule: xx goes to 11

        2. The derivative of the constant 1-1 is zero.

        The result is: 11

      The result of the chain rule is:

      1x1\frac{1}{x - 1}

    Now plug in to the quotient rule:

    (2x2)log(x1)(x1)2x1log(x1)2\frac{\left(2 x - 2\right) \log{\left(x - 1 \right)} - \frac{\left(x - 1\right)^{2}}{x - 1}}{\log{\left(x - 1 \right)}^{2}}

  2. Now simplify:

    x+2(x1)log(x1)+1log(x1)2\frac{- x + 2 \left(x - 1\right) \log{\left(x - 1 \right)} + 1}{\log{\left(x - 1 \right)}^{2}}


The answer is:

x+2(x1)log(x1)+1log(x1)2\frac{- x + 2 \left(x - 1\right) \log{\left(x - 1 \right)} + 1}{\log{\left(x - 1 \right)}^{2}}

The graph
02468-8-6-4-2-1010-200200
The first derivative [src]
                      3 /     1       log(x - 1)\
               (x - 1) *|- -------- + ----------|
                        |         2           2 |
     1                  \  (x - 1)     (x - 1)  /
------------ + ----------------------------------
/log(x - 1)\                 2                   
|----------|              log (x - 1)            
\  x - 1   /                                     
(x1)3(log(x1)(x1)21(x1)2)log(x1)2+11x1log(x1)\frac{\left(x - 1\right)^{3} \left(\frac{\log{\left(x - 1 \right)}}{\left(x - 1\right)^{2}} - \frac{1}{\left(x - 1\right)^{2}}\right)}{\log{\left(x - 1 \right)}^{2}} + \frac{1}{\frac{1}{x - 1} \log{\left(x - 1 \right)}}
The second derivative [src]
/         1     \                      -1 + log(-1 + x)              
|1 - -----------|*(-1 + log(-1 + x)) - ---------------- + log(-1 + x)
\    log(-1 + x)/                        log(-1 + x)                 
---------------------------------------------------------------------
                                2                                    
                             log (-1 + x)                            
(11log(x1))(log(x1)1)log(x1)1log(x1)+log(x1)log(x1)2\frac{\left(1 - \frac{1}{\log{\left(x - 1 \right)}}\right) \left(\log{\left(x - 1 \right)} - 1\right) - \frac{\log{\left(x - 1 \right)} - 1}{\log{\left(x - 1 \right)}} + \log{\left(x - 1 \right)}}{\log{\left(x - 1 \right)}^{2}}
The third derivative [src]
                                                                                                                                                                             /         1     \                      /         2     \                   
                                                                                                                                                                             |1 - -----------|*(-1 + log(-1 + x))   |1 - -----------|*(-1 + log(-1 + x))
                    /         1     \                        6*(-1 + log(-1 + x))   3*(-3 + 2*log(-1 + x))   3*(-1 + log(-1 + x))     /         1     \                      \    log(-1 + x)/                      \    log(-1 + x)/                   
3 - 2*log(-1 + x) - |1 - -----------|*(-3 + 2*log(-1 + x)) - -------------------- + ---------------------- + -------------------- + 4*|1 - -----------|*(-1 + log(-1 + x)) - ------------------------------------ - ------------------------------------
                    \    log(-1 + x)/                            log(-1 + x)             log(-1 + x)                2                 \    log(-1 + x)/                                  log(-1 + x)                            log(-1 + x)             
                                                                                                                 log (-1 + x)                                                                                                                           
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                             2                                                                                                                          
                                                                                                                 (-1 + x)*log (-1 + x)                                                                                                                  
(12log(x1))(log(x1)1)log(x1)+4(11log(x1))(log(x1)1)(11log(x1))(log(x1)1)log(x1)(11log(x1))(2log(x1)3)6(log(x1)1)log(x1)+3(log(x1)1)log(x1)2+3(2log(x1)3)log(x1)2log(x1)+3(x1)log(x1)2\frac{- \frac{\left(1 - \frac{2}{\log{\left(x - 1 \right)}}\right) \left(\log{\left(x - 1 \right)} - 1\right)}{\log{\left(x - 1 \right)}} + 4 \left(1 - \frac{1}{\log{\left(x - 1 \right)}}\right) \left(\log{\left(x - 1 \right)} - 1\right) - \frac{\left(1 - \frac{1}{\log{\left(x - 1 \right)}}\right) \left(\log{\left(x - 1 \right)} - 1\right)}{\log{\left(x - 1 \right)}} - \left(1 - \frac{1}{\log{\left(x - 1 \right)}}\right) \left(2 \log{\left(x - 1 \right)} - 3\right) - \frac{6 \left(\log{\left(x - 1 \right)} - 1\right)}{\log{\left(x - 1 \right)}} + \frac{3 \left(\log{\left(x - 1 \right)} - 1\right)}{\log{\left(x - 1 \right)}^{2}} + \frac{3 \left(2 \log{\left(x - 1 \right)} - 3\right)}{\log{\left(x - 1 \right)}} - 2 \log{\left(x - 1 \right)} + 3}{\left(x - 1\right) \log{\left(x - 1 \right)}^{2}}