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Derivative of log((x+2)/(-x+2))

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

You have entered [src]
   /x + 2 \
log|------|
   \-x + 2/
log(x+22x)\log{\left(\frac{x + 2}{2 - x} \right)}
log((x + 2)/(-x + 2))
Detail solution
  1. Let u=x+22xu = \frac{x + 2}{2 - x}.

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

  3. Then, apply the chain rule. Multiply by ddxx+22x\frac{d}{d x} \frac{x + 2}{2 - x}:

    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)=x+2f{\left(x \right)} = x + 2 and g(x)=2xg{\left(x \right)} = 2 - x.

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

      1. Differentiate x+2x + 2 term by term:

        1. The derivative of the constant 22 is zero.

        2. Apply the power rule: xx goes to 11

        The result is: 11

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

      1. Differentiate 2x2 - x term by term:

        1. The derivative of the constant 22 is zero.

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

          1. Apply the power rule: xx goes to 11

          So, the result is: 1-1

        The result is: 1-1

      Now plug in to the quotient rule:

      4(2x)2\frac{4}{\left(2 - x\right)^{2}}

    The result of the chain rule is:

    4(2x)(2x)2(x+2)\frac{4 \left(2 - x\right)}{\left(2 - x\right)^{2} \left(x + 2\right)}

  4. Now simplify:

    4x24- \frac{4}{x^{2} - 4}


The answer is:

4x24- \frac{4}{x^{2} - 4}

The graph
02468-8-6-4-2-1010-2525
The first derivative [src]
/  1        x + 2  \         
|------ + ---------|*(-x + 2)
|-x + 2           2|         
\         (-x + 2) /         
-----------------------------
            x + 2            
(2x)(12x+x+2(2x)2)x+2\frac{\left(2 - x\right) \left(\frac{1}{2 - x} + \frac{x + 2}{\left(2 - x\right)^{2}}\right)}{x + 2}
The second derivative [src]
/    2 + x \ /    1        1  \
|1 - ------|*|- ------ - -----|
\    -2 + x/ \  -2 + x   2 + x/
-------------------------------
             2 + x             
(1x+2x2)(1x+21x2)x+2\frac{\left(1 - \frac{x + 2}{x - 2}\right) \left(- \frac{1}{x + 2} - \frac{1}{x - 2}\right)}{x + 2}
The third derivative [src]
  /    2 + x \ /    1          1              1        \
2*|1 - ------|*|--------- + -------- + ----------------|
  \    -2 + x/ |        2          2   (-2 + x)*(2 + x)|
               \(-2 + x)    (2 + x)                    /
--------------------------------------------------------
                         2 + x                          
2(1x+2x2)(1(x+2)2+1(x2)(x+2)+1(x2)2)x+2\frac{2 \left(1 - \frac{x + 2}{x - 2}\right) \left(\frac{1}{\left(x + 2\right)^{2}} + \frac{1}{\left(x - 2\right) \left(x + 2\right)} + \frac{1}{\left(x - 2\right)^{2}}\right)}{x + 2}