Mister Exam

Derivative of 1/(x(x+2))

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

The graph:

from to

Piecewise:

The solution

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

  2. Apply the power rule: 1u\frac{1}{u} goes to 1u2- \frac{1}{u^{2}}

  3. Then, apply the chain rule. Multiply by ddxx(x+2)\frac{d}{d x} x \left(x + 2\right):

    1. Apply the product rule:

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

      f(x)=xf{\left(x \right)} = x; to find ddxf(x)\frac{d}{d x} f{\left(x \right)}:

      1. Apply the power rule: xx goes to 11

      g(x)=x+2g{\left(x \right)} = x + 2; to find ddxg(x)\frac{d}{d x} g{\left(x \right)}:

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

        1. Apply the power rule: xx goes to 11

        2. The derivative of the constant 22 is zero.

        The result is: 11

      The result is: 2x+22 x + 2

    The result of the chain rule is:

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

  4. Now simplify:

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


The answer is:

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

The graph
02468-8-6-4-2-1010-100100
The first derivative [src]
    1               
---------*(-2 - 2*x)
x*(x + 2)           
--------------------
     x*(x + 2)      
1x(x+2)(2x2)x(x+2)\frac{\frac{1}{x \left(x + 2\right)} \left(- 2 x - 2\right)}{x \left(x + 2\right)}
The second derivative [src]
  /     1 + x   1 + x           /1     1  \\
2*|-1 + ----- + ----- + (1 + x)*|- + -----||
  \       x     2 + x           \x   2 + x//
--------------------------------------------
                 2        2                 
                x *(2 + x)                  
2((x+1)(1x+2+1x)+x+1x+21+x+1x)x2(x+2)2\frac{2 \left(\left(x + 1\right) \left(\frac{1}{x + 2} + \frac{1}{x}\right) + \frac{x + 1}{x + 2} - 1 + \frac{x + 1}{x}\right)}{x^{2} \left(x + 2\right)^{2}}
The third derivative [src]
  /                                                                                    /1     1  \           /1     1  \            \
  |                                                                            (1 + x)*|- + -----|   (1 + x)*|- + -----|            |
  |4     4     3*(1 + x)   3*(1 + x)             /1       1           1    \           \x   2 + x/           \x   2 + x/   4*(1 + x)|
2*|- + ----- - --------- - --------- - 2*(1 + x)*|-- + -------- + ---------| - ------------------- - ------------------- - ---------|
  |x   2 + x        2              2             | 2          2   x*(2 + x)|            x                   2 + x          x*(2 + x)|
  \                x        (2 + x)              \x    (2 + x)             /                                                        /
-------------------------------------------------------------------------------------------------------------------------------------
                                                              2        2                                                             
                                                             x *(2 + x)                                                              
2(2(x+1)(1(x+2)2+1x(x+2)+1x2)(x+1)(1x+2+1x)x+23(x+1)(x+2)2+4x+2(x+1)(1x+2+1x)x4(x+1)x(x+2)+4x3(x+1)x2)x2(x+2)2\frac{2 \left(- 2 \left(x + 1\right) \left(\frac{1}{\left(x + 2\right)^{2}} + \frac{1}{x \left(x + 2\right)} + \frac{1}{x^{2}}\right) - \frac{\left(x + 1\right) \left(\frac{1}{x + 2} + \frac{1}{x}\right)}{x + 2} - \frac{3 \left(x + 1\right)}{\left(x + 2\right)^{2}} + \frac{4}{x + 2} - \frac{\left(x + 1\right) \left(\frac{1}{x + 2} + \frac{1}{x}\right)}{x} - \frac{4 \left(x + 1\right)}{x \left(x + 2\right)} + \frac{4}{x} - \frac{3 \left(x + 1\right)}{x^{2}}\right)}{x^{2} \left(x + 2\right)^{2}}