Mister Exam

Derivative of log(x+1)/(x+1)

Function f() - derivative -N order at the point
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The graph:

from to

Piecewise:

The solution

You have entered [src]
log(x + 1)
----------
  x + 1   
log(x+1)x+1\frac{\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)=log(x+1)f{\left(x \right)} = \log{\left(x + 1 \right)} and g(x)=x+1g{\left(x \right)} = x + 1.

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

    1. Let u=x+1u = 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(x+1)\frac{d}{d x} \left(x + 1\right):

      1. Differentiate x+1x + 1 term by term:

        1. Apply the power rule: xx goes to 11

        2. The derivative of the constant 11 is zero.

        The result is: 11

      The result of the chain rule is:

      1x+1\frac{1}{x + 1}

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

    1. Differentiate x+1x + 1 term by term:

      1. The derivative of the constant 11 is zero.

      2. Apply the power rule: xx goes to 11

      The result is: 11

    Now plug in to the quotient rule:

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

  2. Now simplify:

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


The answer is:

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

The graph
02468-8-6-4-2-1010-500500
The first derivative [src]
   1       log(x + 1)
-------- - ----------
       2           2 
(x + 1)     (x + 1)  
log(x+1)(x+1)2+1(x+1)2- \frac{\log{\left(x + 1 \right)}}{\left(x + 1\right)^{2}} + \frac{1}{\left(x + 1\right)^{2}}
The second derivative [src]
-3 + 2*log(1 + x)
-----------------
            3    
     (1 + x)     
2log(x+1)3(x+1)3\frac{2 \log{\left(x + 1 \right)} - 3}{\left(x + 1\right)^{3}}
The third derivative [src]
11 - 6*log(1 + x)
-----------------
            4    
     (1 + x)     
116log(x+1)(x+1)4\frac{11 - 6 \log{\left(x + 1 \right)}}{\left(x + 1\right)^{4}}
The graph
Derivative of log(x+1)/(x+1)