Mister Exam

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

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

The graph:

from to

Piecewise:

The solution

You have entered [src]
        log(x)
x - 1 - ------
          x   
(x1)log(x)x\left(x - 1\right) - \frac{\log{\left(x \right)}}{x}
x - 1 - log(x)/x
Detail solution
  1. Differentiate (x1)log(x)x\left(x - 1\right) - \frac{\log{\left(x \right)}}{x} term by term:

    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

    2. The derivative of a constant times a function is the constant times the derivative of the function.

      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)=log(x)f{\left(x \right)} = \log{\left(x \right)} and g(x)=xg{\left(x \right)} = x.

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

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

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

        1. Apply the power rule: xx goes to 11

        Now plug in to the quotient rule:

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

      So, the result is: 1log(x)x2- \frac{1 - \log{\left(x \right)}}{x^{2}}

    The result is: 11log(x)x21 - \frac{1 - \log{\left(x \right)}}{x^{2}}

  2. Now simplify:

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


The answer is:

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

The graph
02468-8-6-4-2-1010-500500
The first derivative [src]
    1    log(x)
1 - -- + ------
     2      2  
    x      x   
1+log(x)x21x21 + \frac{\log{\left(x \right)}}{x^{2}} - \frac{1}{x^{2}}
The second derivative [src]
3 - 2*log(x)
------------
      3     
     x      
32log(x)x3\frac{3 - 2 \log{\left(x \right)}}{x^{3}}
The third derivative [src]
-11 + 6*log(x)
--------------
       4      
      x       
6log(x)11x4\frac{6 \log{\left(x \right)} - 11}{x^{4}}